How to Configure IOS SLB Features [Cisco IOS 15.2S]

How to Configure Required and Optional IOS SLB Functions

To configure IOS SLB functions, perform the tasks in the following sections. Required and optional tasks are indicated.

How to Configure a Server Farm and a Real Server
How to Configure a Virtual Server
How to Verify a Virtual Server
How to Verify a Server Farm
How to Verify Clients
How to Verify IOS SLB Connectivity

How to Configure a Server Farm and a Real Server

Perform this required task to configure a server farm and a real server.

Note

You cannot configure IOS SLB from different user sessions at the same time.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb serverfarm server-farm

4. access interface

5. bindid [bind-id]

6. nat {client pool | server}

7. predictor [roundrobin| leastconns| route-map mapname]

8. probe probe

9. real ipv4-address [ipv6 ipv6-address] [port]

10. faildetect numconns number-of-conns [numclients number-of-clients]

11. maxclients number-of-conns

12. maxconns number-of-conns [sticky-override]

13. reassign threshold

14. retry retry-value

15. weight setting

16. inservice

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode. If prompted, enter your password.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

ip slb serverfarm server-farm

Example:

Router(config)# ip slb serverfarm PUBLIC

Adds a server farm definition to the IOS SLB configuration and enters server farm configuration mode.

Step 4

access interface

Example:

Router(config-slb-sfarm)# access GigabitEthernet 0/1.1

(Optional) Configures an access interface or subinterface for a server farm.

Step 5

bindid [bind-id]

Example:

Router(config-slb-sfarm)# bindid 309

(Optional) Specifies a bind ID on the server farm for use by Dynamic Feedback Protocol (DFP).

Note

GPRS load balancing and Home Agent Director do not support this command.

Step 6

nat {client pool | server}

Example:

Router(config-slb-sfarm)# nat server

(Optional) Configures Network Address Translation (NAT) client translation mode or NAT server address translation mode on the server farm.

All IPv4 or IPv6 server farms that are associated with the same virtual server must have the same NAT configuration.

Step 7

predictor [roundrobin| leastconns| route-map mapname]

Example:

Router(config-slb-sfarm)# predictor leastconns

(Optional) Specifies the algorithm to be used to determine how a real server is selected.

Note

RADIUS load balancing requires the default setting (the weighted round robin algorithm). In GPRS load balancing without GTP cause code inspection enabled, you must accept the default setting (the weighted round robin algorithm). The Home Agent Director requires the default setting (the weighted round robin algorithm). When you specify the predictor route-map command in SLB server farm configuration mode, no further commands in SLB server farm configuration mode or real server configuration mode are allowed.

For more details, see the following sections:

"Weighted Round Robin Algorithm"
"Weighted Least Connections Algorithm"
"Route Map Algorithm"

Step 8

probe probe

Example:

Router(config-slb-sfarm)# probe PROBE1

(Optional) Associates a probe with the real server.

Step 9

real ipv4-address [ipv6 ipv6-address] [port]

Example:

Router(config-slb-sfarm)# real 10.1.1.1

Identifies a real server by IPv4 address, and optional IPv6 address and port number, as a member of a server farm and enters real server configuration mode.

Note

In GPRS load balancing, specify the IP addresses (virtual template addresses, for Cisco GGSNs) of the real servers performing the GGSN function. In VPN server load balancing, specify the IP addresses of the real servers acting as VPN terminators. For the Home Agent Director, specify the IP addresses of the real servers acting as home agents. For dual-stack support for GTP load balancing, specify the real server's IPv4 and IPv6 address.

Step 10

faildetect numconns number-of-conns [numclients number-of-clients]

Example:

Router(config-slb-real)# faildetect numconns 10 numclients 3

(Optional) Specifies the number of consecutive connection failures and, optionally, the number of unique client connection failures, that constitute failure of the real server.

In GPRS load balancing, if only one SGSN is configured in your environment, specify the numclients keyword with a value of 1.
In RADIUS load balancing, for automatic session-based failure detection, specify the numclients keyword with a value of 1.

Step 11

maxclients number-of-conns

Example:

Router(config-slb-real)# maxclients 10

(Optional) Specifies the maximum number of IOS SLB RADIUS and GTP sticky subscribers that can be assigned to an individual virtual server.

Step 12

maxconns number-of-conns [sticky-override]

Example:

Router(config-slb-real)# maxconns 1000

(Optional) Specifies the maximum number of active connections allowed on the real server at one time.

Step 13

reassign threshold

Example:

Router(config-slb-real)# reassign 2

(Optional) Specifies the threshold of consecutive unacknowledged SYNchronize sequence numbers (SYNs) or Create Packet Data Protocol (PDP) requests that, if exceeded, result in an attempted connection to a different real server.

Note

In GPRS load balancing, you must specify a reassign threshold less than the SGSN's N3-REQUESTS counter value.

Step 14

retry retry-value

Example:

Router(config-slb-real)# retry 120

(Optional) Specifies the time interval, in seconds, to wait between the detection of a server failure and the next attempt to connect to the failed server.

Step 15

weight setting

Example:

Router(config-slb-real)# weight 24

(Optional) Specifies the real server workload capacity relative to other servers in the server farm.

Note

If you use Dynamic Feedback Protocol (DFP), the static weights you define using the weight command in server farm configuration mode are overridden by the weights calculated by DFP. If DFP is removed from the network, IOS SLB reverts to the static weights.

Step 16

inservice

Example:

Router(config-slb-real)# inservice

Enables the real server for use by IOS SLB.

What to Do Next

Note

When performing server load balancing and firewall load balancing together on a Cisco Catalyst 6500 Family Switch, use the mls ip slb wildcard search rp command to reduce the probability of exceeding the capacity of the Telecommunications Access Method (TCAM) on the Policy Feature Card (PFC). See "How to Configure a Wildcard Search" for more details.

How to Configure a Virtual Server

Perform this required task to configure a virtual server. IOS SLB supports up to 500 virtual servers.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb vserver virtual-server

4. Do one of the following:

virtual ipv4-address [ipv4-netmask[group]] {esp| gre| protocol}
virtual ipv4-address [ipv4-netmask[group]] [ipv6 ipv6-address [prefix ipv6-prefix]] {tcp| udp} [port| any] [service service]

5. serverfarm primary-farm [backup backup-farm[sticky]] [ipv6-primary ipv6-primary-farm[ipv6-backup ipv6-backup-farm]] [map map-id priority priority]

6. access interface [route framed-ip]

7. advertise [active]

8. client {ipv4-address netmask[exclude] | gtp carrier-code [code]}

9. delay {duration | radius framed-ip duration}

10. gtp notification cac [reassign-count]

11. gtp session

12. gw port port

13. hand-off radius duration

14. idle [asn request duration | asn msid msid | gtp imsi duration [query [max-queries]] | gtp request duration | ipmobile request duration | radius {request | framed-ip} duration]

15. purge radius framed-ip acct on-off

16. purge radius framed-ip acct stop {attribute-number | {26| vsa} {vendor-ID | 3gpp| 3gpp2} sub-attribute-number}

17. radius acct local-ack key [encrypt] secret-string

18. radius inject auth group-number {calling-station-id | username}

19. radius inject auth timer seconds

20. radius inject auth vsa vendor-id

21. replicate casa listen-ip remote-ip port [interval] [password [encrypt] secret-string timeout]

22. replicate interval interval

23. replicate slave

24. sticky {duration[group group-id] [netmask netmask] | asn msid[group group-id] | gtp imsi[group group-id] | radius calling-station-id| radius framed-ip[group group-id] | radius username[msid-cisco] [group group-id]}

25. synguard syn-count interval

26. inservice [standby group-name] [active]

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode. If prompted, enter your password if prompted.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

ip slb vserver virtual-server

Example:

Router(config)# ip slb vserver PUBLIC_HTTP

Identifies a virtual server and enters virtual server configuration mode.

Step 4

Do one of the following:

virtual ipv4-address [ipv4-netmask[group]] {esp| gre| protocol}
virtual ipv4-address [ipv4-netmask[group]] [ipv6 ipv6-address [prefix ipv6-prefix]] {tcp| udp} [port| any] [service service]

Example:

Router(config-slb-vserver)# virtual 10.0.0.1 tcp www

Specifies the virtual server IP address, type of connection, and optional TCP or User Datagram Protocol (UDP) port number, Internet Key Exchange (IKE) or Wireless Session Protocol (WSP) setting, and service coupling.

Note

For RADIUS load balancing, specify the service radiuskeyword option.

Note

For ASN load balancing, specify the service asnkeyword option.

Note

For GPRS load balancing:

- Specify a virtual GGSN IP address as the virtual server, and specify the udp keyword option.
- To load-balance GTP v1 and GTP v2 sessions, specify port number 2123, if the GGSNs and SGSNs are in compliance with the ETSI standard, or specify port number 0 or any to configure an all-port virtual server (that is, a virtual server that accepts flows destined for all ports).
- To load-balance GTP v0 sessions, specify port number 3386, if the GGSNs and SGSNs are in compliance with the ETSI standard, or specify port number 0 or anyto configure an all-port virtual server.
- To enable GPRS load balancing without GTP cause code inspection, specify the service gtpkeyword option.
- To enable GPRS load balancing with GTP cause code inspection, specify the service gtp-inspectkeyword option.
- For dual-stack support for GTP load balancing, specify the virtual server's IPv4 and IPv6 addresses and optional IPv6 prefix.

Step 5

serverfarm primary-farm [backup backup-farm[sticky]] [ipv6-primary ipv6-primary-farm[ipv6-backup ipv6-backup-farm]] [map map-id priority priority]

Example:

Router(config-slb-vserver)# serverfarm SF1 backup SF2 map 1 priority 1

Associates a real server farm with a virtual server, and optionally configures a backup server farm and specifies that sticky connections are to be used in the backup server farm.

Note

RADIUS load balancing and the Home Agent Director do not support the stickykeyword. You can associate more than one server farm with a given RADIUS virtual server by configuring more than one serverfarm command, each with a unique map ID and a unique priority. (That is, each map ID and each map priority must be unique across all server farms associated with the virtual server.) For GPRS load balancing, if a real server is defined in two or more server farms, each server farm must be associated with a different virtual server. For dual-stack support for GTP load balancing, specify the primary IPv6 server farm and optional backup IPv6 server farm. All IPv4 or IPv6 server farms that are associated with the same virtual server must have the same NAT configuration.

Step 6

access interface [route framed-ip]

Example:

Router(config-slb-vserver)# access Vlan20 route framed-ip

(Optional) Enables framed-IP routing to inspect the ingress interface.

Step 7

advertise [active]

Example:

Router(config-slb-vserver)# advertise

(Optional) Controls the installation of a static route to the Null0 interface for a virtual server address.

Step 8

client {ipv4-address netmask[exclude] | gtp carrier-code [code]}

Example:

Router(config-slb-vserver)# client 10.4.4.0 255.255.255.0

(Optional) Specifies which clients are allowed to use the virtual server.

Note

GPRS load balancing supports only the gtp carrier-code option, and only if GTP cause code inspection is enabled. Dual-stack support for GTP load balancing does not support this command.

Step 9

delay {duration | radius framed-ip duration}

Example:

Router(config-slb-vserver)# delay 30

(Optional) Specifies the time IOS SLB maintains TCP connection context after a connection has ended.

Step 10

gtp notification cac [reassign-count]

Example:

Router(config-slb-vserver)# gtp notification cac 5

(Optional) Limits the number of times IOS SLB can reassign a session to a new real server for GGSN-IOS SLB messaging.

Step 11

gtp session

Example:

Router(config-slb-vserver)# no gtp session

(Optional) Enables IOS SLB to create GTP load-balancing sessions. This is the default setting.

To enable sticky-only load balancing for GTP, use the no form of this command:

no gtp session

If you enable sticky-only load balancing, you must also enable sticky connections for the virtual server using the sticky (virtual server)command.

Step 12

gw port port

Example:

Router(config-slb-vserver)# gw port 63082

(Optional) Specifies the port that the Cisco Broadband Wireless Gateway (BWG) is to use to communicate with IOS SLB.

Step 13

hand-off radius duration

Example:

Router(config-slb-vserver)# hand-off radius 30

(Optional) Changes the amount of time IOS SLB waits for an ACCT-START message from a new Mobile IP foreign agent in the event of a foreign agent hand-off.

Step 14

idle [asn request duration | asn msid msid | gtp imsi duration [query [max-queries]] | gtp request duration | ipmobile request duration | radius {request | framed-ip} duration]

Example:

Router(config-slb-vserver)# idle 120

(Optional) Specifies the minimum time IOS SLB maintains connection context in the absence of packet activity.

Note

In GPRS load balancing without GTP cause code inspection enabled, specify an idle timer greater than the longest possible interval between PDP context requests on the SGSN.

Step 15

purge radius framed-ip acct on-off

Example:

Router(config-slb-vserver)# purge radius framed-ip acct on-off

(Optional) Enables IOS SLB to purge entries in the IOS SLB RADIUS framed-IP sticky database upon receipt of an Accounting On or Off message.

Step 16

purge radius framed-ip acct stop {attribute-number | {26| vsa} {vendor-ID | 3gpp| 3gpp2} sub-attribute-number}

Example:

Router(config-slb-vserver)# purge radius framed-ip acct stop 44

(Optional) Enables IOS SLB to purge entries in the IOS SLB RADIUS framed-IP sticky database upon receipt of an Accounting-Stop message.

Step 17

radius acct local-ack key [encrypt] secret-string

Example:

Router(config-slb-vserver)# radius acct local-ack key SECRET_PASSWORD

(Optional) Enables a RADIUS virtual server to acknowledge RADIUS accounting messages.

Step 18

radius inject auth group-number {calling-station-id | username}

Example:

Router(config-slb-vserver)# radius inject auth 1 calling-station-id

(Optional) Configures a vendor-specific attribute (VSA) correlation group for an IOS SLB RADIUS load balancing accelerated data plane forwarding authentication virtual server, and specifies whether IOS SLB is to create VSA correlation entries based on RADIUS calling station IDs or RADIUS usernames.

Step 19

radius inject auth timer seconds

Example:

Router(config-slb-vserver)# radius inject auth timer 45

(Optional) Configures a timer for VSA correlation for an IOS SLB RADIUS load balancing accelerated data plane forwarding authentication virtual server.

Step 20

radius inject auth vsa vendor-id

Example:

Router(config-slb-vserver)# radius inject auth vsa vendor1

(Optional) Buffers VSAs for VSA correlation for an IOS SLB RADIUS load balancing accelerated data plane forwarding authentication virtual server.

Step 21

replicate casa listen-ip remote-ip port [interval] [password [encrypt] secret-string timeout]

Example:

Router(config-slb-vserver)# replicate casa 10.10.10.11 10.10.11.12 4231

(Optional) Configures a stateful backup of IOS SLB decision tables to a backup switch.

Note

The Home Agent Director does not support this command. If you specify the service gtpkeyword on the virtual command, and you do not specify the stickycommand with the gtp imsikeyword, the replicate casacommand is not supported (because sessions are not persistent, and there is nothing to replicate).

Step 22

replicate interval interval

Example:

Router(config-slb-vserver)# replicate interval 20

(Optional) Sets the replication delivery interval for an IOS SLB virtual server.

Note

The Home Agent Director does not support this command. If you specify the service gtpkeyword on the virtual command, and you do not specify the stickycommand with the gtp imsikeyword, the replicate casacommand is not supported (because sessions are not persistent, and there is nothing to replicate).

Step 23

replicate slave

Example:

Router(config-slb-vserver)# replicate slave

(Optional) Enables stateful backup of redundant route processors for an IOS SLB virtual server.

Note

The Home Agent Director does not support this command. If you specify the service gtpkeyword on the virtual command, and you do not specify the stickycommand with the gtp imsikeyword, the replicate casacommand is not supported (because sessions are not persistent, and there is nothing to replicate). If you are using one Supervisor Engine with replicate slave configured, you might receive out-of-sync messages on the Supervisor.

Step 24

sticky {duration[group group-id] [netmask netmask] | asn msid[group group-id] | gtp imsi[group group-id] | radius calling-station-id| radius framed-ip[group group-id] | radius username[msid-cisco] [group group-id]}

Example:

Router(config-slb-vserver)# sticky 60 group 10

(Optional) Specifies that connections from the same client use the same real server, as long as the interval between client connections does not exceed the specified duration.

Note

In VPN server load balancing, specify a duration of at least 15 seconds. GPRS load balancing and the Home Agent Director do not support this command.

Step 25

synguard syn-count interval

Example:

Router(config-slb-vserver)# synguard 50

(Optional) Specifies the rate of TCP SYNchronize sequence numbers (SYNs) managed by a virtual server in order to prevent a SYN flood denial-of-service attack.

Note

GPRS load balancing and the Home Agent Director do not support this command.

Step 26

inservice [standby group-name] [active]

Example:

Router(config-slb-vserver)# inservice

Enables the virtual server for use by IOS SLB.

How to Verify a Virtual Server

Perform the following optional task to verify a virtual server.

The following show ip slb vservers command verifies the configuration of the virtual servers PUBLIC_HTTP and RESTRICTED_HTTP:

Router# show ip slb vservers
slb vserver      prot  virtual               state         conns
-------------------------------------------------------------------
PUBLIC_HTTP      TCP   10.0.0.1:80           OPERATIONAL     0
RESTRICTED_HTTP  TCP   10.0.0.2:80           OPERATIONAL     0
Router#

How to Verify a Server Farm

Perform the following optional task to verify a server farm.

The following show ip slb reals command shows the status of server farms PUBLIC and RESTRICTED, the associated real servers, and their status:

Router# show ip slb real
real                    farm name        weight   state          conns
---------------------------------------------------------------------
10.1.1.1                 PUBLIC           8       OPERATIONAL      0
10.1.1.2                 PUBLIC           8       OPERATIONAL      0
10.1.1.3                 PUBLIC           8       OPERATIONAL      0
10.1.1.20                RESTRICTED       8       OPERATIONAL      0
10.1.1.21                RESTRICTED       8       OPERATIONAL      0
Router#

The following show ip slb serverfarmcommand displays the configuration and status of server farms PUBLIC and RESTRICTED:

Router# show ip slb serverfarm
server farm      predictor    nat   reals   bind id
---------------------------------------------------
PUBLIC           ROUNDROBIN   none  3       0
RESTRICTED       ROUNDROBIN   none  2       0
Router#

How to Verify Clients

Perform the following optional task to verify clients.

The following show ip slb conns command verifies the restricted client access and status:

Router# show ip slb conns
vserver         prot client                real                  state     nat
-------------------------------------------------------------------------------
RESTRICTED_HTTP TCP  10.4.4.0:80           10.1.1.20             CLOSING   none
Router#

The following show ip slb conns command shows detailed information about the restricted client access status:

Router# show ip slb conns client 10.4.4.0 detail
VSTEST_UDP, client = 10.4.4.0:80
  state = CLOSING, real = 10.1.1.20, nat = none
  v_ip = 10.0.0.2:80, TCP, service = NONE
  client_syns = 0, sticky = FALSE, flows attached = 0
Router#

How to Verify IOS SLB Connectivity

Perform the following optional task to verify IOS SLB connectivity.

To verify that the IOS SLB feature is installed and is operating correctly, ping the real servers from the IOS SLB switch, then ping the virtual servers from the clients.

The following show ip slb stats command shows detailed information about the IOS SLB network status:

Router# show ip slb stats
 Pkts via normal switching:  0
 Pkts via special switching: 6
 Pkts dropped:               0
 Connections Created:        1
 Connections Established:    1
 Connections Destroyed:      0
 Connections Reassigned:     0
 Zombie Count:               0
 Connections Reused:         0

Normal switching exists when IOS SLB packets are managed on normal IOS switching paths (CEF, fast switching, and process level switching).
Special switching exists when IOS SLB packets are managed on hardware-assisted switching paths.

See "How to Monitor and Maintain the Cisco IOS SLB Feature" for additional commands used to verify IOS SLB networks and connections.

How to Configure Firewall Load Balancing

Perform the following tasks to configure a basic IOS SLB firewall load-balancing network.

IOS SLB firewall load balancing uses probes to detect and recover from failures. You must configure a probe on each real server in the firewall farm. Ping probes are recommended; see "How to Configure a Ping Probe" for more details. If a firewall does not allow ping probes to be forwarded, use HTTP probes instead. See "How to Configure an HTTP Probe" for more details. You can configure more than one probe, in any combination of supported types (DNS, HTTP, TCP, or ping), for each firewall in a firewall farm.

When you perform server load balancing and firewall load balancing together on a Cisco Catalyst 6500 switch, use the mls ip slb wildcard search rp command in global configuration mode to reduce the probability of exceeding the capacity of the Telecommunications Access Method (TCAM) on the Policy Feature Card (PFC). See "How to Configure a Wildcard Search" for more details.

If IOS SLB experiences a high purge rate, the CPU might be impacted. If this problem occurs, use the no form of the mls ip slb purge global command in global configuration mode to disable purge throttling on TCP and UDP flow packets. See "How to Configure Protocol-Level Purging of MLS Entries" for more details.

This section describes the following IOS SLB firewall load-balancing configuration tasks. Required and optional tasks are indicated.

How to Configure a Firewall Farm
How to Verify a Firewall Farm
How to Verify Firewall Connectivity

How to Configure a Firewall Farm

Perform the following required task to configure a firewall farm.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb firewallfarm firewall-farm

4. real ip-address

5. probe probe

6. weight setting

7. inservice

8. access [source source-ip netmask | destination destination-ip netmask | inbound {inbound-interface | datagram connection} | outbound outbound-interface]

9. predictor hash address [port]

10. purge connection

11. purge sticky

12. replicate casa listen-ip remote-ip port [interval] [password [encrypt] secret-string[timeout]]

13. replicate interval interval

14. replicate slave

15. protocol tcp

16. delay duration

17. idle duration

18. maxconns maximum-number

19. sticky duration [netmask netmask] [source| destination]

20. protocol datagram

21. idle duration

22. maxconns maximum-number

23. sticky duration [netmask netmask] [source| destination]

24. inservice

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode. If prompted, enter your password.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

ip slb firewallfarm firewall-farm

Example:

Router(config)# ip slb firewallfarm FIRE1

Adds a firewall farm definition to the IOS SLB configuration and enters firewall farm configuration mode.

Step 4

real ip-address

Example:

Router(config-slb-fw)# real 10.1.1.1

Identifies a firewall by IP address as a member of a firewall farm and enters real server configuration mode.

Step 5

probe probe

Example:

Router(config-slb-fw-real)# probe FireProbe

Associates a probe with the firewall.

Step 6

weight setting

Example:

Router(config-slb-fw-real)# weight 24

(Optional) Specifies the firewall's workload capacity relative to other firewalls in the firewall farm.

Step 7

inservice

Example:

Router(config-slb-fw-real)# inservice

Enables the firewall for use by the firewall farm and by IOS SLB.

Step 8

access [source source-ip netmask | destination destination-ip netmask | inbound {inbound-interface | datagram connection} | outbound outbound-interface]

Example:

Router(config-slb-fw)# access destination 10.1.6.0 255.255.255.0

(Optional) Routes specific flows to a firewall farm.

Step 9

predictor hash address [port]

Example:

Router(config-slb-fw)# predictor hash address

(Optional) Specifies whether the source and destination TCP or User Datagram Protocol (UDP) port numbers, in addition to the source and destination IP addresses, are to be used when selecting a firewall.

Step 10

purge connection

Example:

Router(config-slb-fw)# purge connection

(Optional) Enables IOS SLB firewall load balancing to send purge requests for connections.

Step 11

purge sticky

Example:

Router(config-slb-fw)# purge sticky

(Optional) Enables IOS SLB firewall load balancing to send purge requests for sticky connections when the sticky timer expires.

Step 12

replicate casa listen-ip remote-ip port [interval] [password [encrypt] secret-string[timeout]]

Example:

Router(config-slb-fw)# replicate casa 10.10.10.11 10.10.11.12 4231

(Optional) Configures a stateful backup of IOS SLB firewall load-balancing decision tables to a backup switch.

Note

The Home Agent Director does not support this command. If you specify the service gtpkeyword on the virtual command, and you do not specify the stickycommand with the gtp imsikeyword, the replicate casacommand is not supported (because sessions are not persistent, and there is nothing to replicate).

Step 13

replicate interval interval

Example:

Router(config-slb-fw)# replicate interval 20

(Optional) Sets the replication delivery interval for an IOS SLB firewall farm.

Note

The Home Agent Director does not support this command. If you specify the service gtpkeyword on the virtual command, and you do not specify the stickycommand with the gtp imsikeyword, the replicate intervalcommand is not supported (because sessions are not persistent, and there is nothing to replicate).

Step 14

replicate slave

Example:

Router(config-slb-fw)# replicate slave

(Optional) Enables stateful backup of redundant route processors for an IOS SLB firewall farm.

Note

The Home Agent Director does not support this command. If you specify the service gtpkeyword on the virtual command, and you do not specify the stickycommand with the gtp imsikeyword, the replicate slavecommand is not supported (because sessions are not persistent, and there is nothing to replicate). If you are using one Supervisor Engine with replicate slave configured, you might receive out-of-sync messages on the Supervisor.

Step 15

protocol tcp

Example:

Router(config-slb-fw)# protocol tcp

(Optional) Enters firewall farm TCP protocol configuration mode.

Step 16

delay duration

Example:

Router(config-slb-fw-tcp)# delay 30

(Optional) In firewall farm TCP protocol configuration mode, specifies the time IOS SLB firewall load balancing maintains TCP connection context after a connection ends.

Step 17

idle duration

Example:

Router(config-slb-fw-tcp)# idle 120

(Optional) In firewall farm TCP protocol configuration mode, specifies the minimum time IOS SLB firewall load balancing maintains connection context in the absence of packet activity.

Step 18

maxconns maximum-number

Example:

Router(config-slb-fw-tcp)# maxconns 1000

(Optional) In firewall farm TCP protocol configuration mode, specifies the maximum number of active TCP connections allowed on the firewall farm at one time.

Step 19

sticky duration [netmask netmask] [source| destination]

Example:

Router(config-slb-fw-tcp)# sticky 60

(Optional) In firewall farm TCP protocol configuration mode, specifies that connections from the same IP address use the same firewall if either of the following conditions is met:

As long as any connection between the same pair of IP addresses exists (source and destination sticky).
For a period, defined by duration , after the last connection is destroyed.

Step 20

protocol datagram

Example:

Router(config-slb-fw)# protocol datagram

(Optional) Enters firewall farm datagram protocol configuration mode.

Step 21

idle duration

Example:

Router(config-slb-fw-udp)# idle 120

(Optional) In firewall farm datagram protocol configuration mode, specifies the minimum time IOS SLB firewall load balancing maintains connection context in the absence of packet activity.

Step 22

maxconns maximum-number

Example:

Router(config-slb-fw-udp)# maxconns 1000

(Optional) In firewall farm datagram protocol configuration mode, specifies the maximum number of active datagram connections allowed on the firewall farm at one time.

Step 23

sticky duration [netmask netmask] [source| destination]

Example:

Router(config-slb-fw-udp)# sticky 60

(Optional) In firewall farm datagram protocol configuration mode, specifies that connections from the same IP address use the same firewall if either of the following conditions is met:

As long as any connection between the same pair of IP addresses exists (source and destination sticky).
For a period, defined by duration , after the last connection is destroyed.

Step 24

inservice

Example:

Router(config-slb-fw)# inservice

Enables the firewall farm for use by IOS SLB.

How to Verify a Firewall Farm

Perform the following optional task to verify a firewall farm.

The following show ip slb reals command shows the status of firewall farm FIRE1, the associated real servers, and the server status:

Router# show ip slb real
real                  farm name        weight   state          conns
--------------------------------------------------------------------
10.1.1.2              FIRE1            8        OPERATIONAL    0
10.1.2.2              FIRE1            8        OPERATIONAL    0

The following show ip slb firewallfarmcommand shows the configuration and status of firewall farm FIRE1:

Router# show ip slb firewallfarm
 
firewall farm    hash        state         reals
------------------------------------------------
FIRE1            IPADDR      INSERVICE     2

How to Verify Firewall Connectivity

Perform the following optional task to verify firewall connectivity.

To verify that IOS SLB firewall load balancing is configured and is operating correctly, perform the following steps:

SUMMARY STEPS

1. Ping the external real servers (the ones outside the firewall) from the IOS SLB firewall load-balancing switch.

2. Ping the internal real servers (the ones inside the firewall) from the clients.

3. Use the show ip slb stats command to show information about the IOS SLB firewall load-balancing network status:

4. Use the show ip slb real detailcommand to show information about the IOS SLB firewall load-balancing real server status:

5. Use the show ip slb connscommand to show information about the active IOS SLB firewall load-balancing connections:

DETAILED STEPS

Step 1	Ping the external real servers (the ones outside the firewall) from the IOS SLB firewall load-balancing switch.
Step 2	Ping the internal real servers (the ones inside the firewall) from the clients.
Step 3	Use the show ip slb stats command to show information about the IOS SLB firewall load-balancing network status: Example: Router# show ip slb stats Pkts via normal switching: 0 Pkts via special switching: 0 Pkts dropped: 0 Connections Created: 1911871 Connections Established: 1967754 Connections Destroyed: 1313251 Connections Reassigned: 0 Zombie Count: 0 Connections Reused: 59752 Connection Flowcache Purges:1776582 Failed Connection Allocs: 17945 Failed Real Assignments: 0 Normal switching exists when IOS SLB packets are managed on normal IOS switching paths (CEF, fast switching, and process level switching). Special switching exists when IOS SLB packets are managed on hardware-assisted switching paths.
Step 4	Use the show ip slb real detailcommand to show information about the IOS SLB firewall load-balancing real server status: Example: Router# show ip slb reals detail 172.16.88.5, SF1, state = OPERATIONAL, type = server ipv6 = 2342:2342:2343:FF04:2388:BB03:3223:8912 conns = 0, dummy_conns = 0, maxconns = 4294967295 weight = 8, weight(admin) = 8, metric = 0, remainder = 0 reassign = 3, retry = 60 failconn threshold = 8, failconn count = 0 failclient threshold = 2, failclient count = 0 total conns established = 0, total conn failures = 0 server failures = 0
Step 5	Use the show ip slb connscommand to show information about the active IOS SLB firewall load-balancing connections: Example: Router# show ip slb conns vserver prot client real state nat ------------------------------------------------------------------------------- FirewallTCP TCP 80.80.50.187:40000 10.1.1.4 ESTAB none FirewallTCP TCP 80.80.50.187:40000 10.1.1.4 ESTAB none FirewallTCP TCP 80.80.50.187:40000 10.1.1.4 ESTAB none FirewallTCP TCP 80.80.50.187:40000 10.1.1.4 ESTAB none FirewallTCP TCP 80.80.50.187:40000 10.1.1.4 ESTAB none

What to Do Next

See "How to Monitor and Maintain the Cisco IOS SLB Feature" for additional commands used to verify IOS SLB networks and connections.

How to Configure a Probe

The following sections describe how to configure and verify probes. By default, no probes are configured in IOS SLB.

IOS SLB uses probes to verify connectivity and detect failures. For a detailed description of each type of probe, see the "Probes" section.

Perform the following task to configure a probe. Required and optional tasks are indicated.

How to Configure a Custom UDP Probe
How to Configure a DNS Probe
How to Configure an HTTP Probe
How to Configure a Ping Probe
How to Configure a TCP Probe
How to Configure a WSP Probe
How to Associate a Probe
How to Verify a Probe

How to Configure a Custom UDP Probe

Perform the following task to configure a custom User Datagram Protocol (UDP) probe.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb probe probe custom udp

4. address [ip-address] [routed]

5. faildetect number-of-probes

6. interval seconds

7. port port

8. request data {start-byte | continue} hex-data-string

9. response clause-number data start-byte hex-data-string

10. timeout seconds

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip slb probe probe custom udp Example: Router(config)# ip slb probe PROBE6 custom udp	Configures the IOS SLB probe name and enters custom User Datagram Protocol (UDP) probe configuration mode.
Step 4	address [ip-address] [routed] Example: Router(config-slb-probe)# address 10.1.1.1	(Optional) Configures an IP address to which to send the custom UDP probe.
Step 5	faildetect number-of-probes Example: Router(config-slb-probe)# faildetect 16	(Optional) Specifies the number of consecutive unacknowledged custom UDP probes that constitute failure of the real server.
Step 6	interval seconds Example: Router(config-slb-probe)# interval 11	(Optional) Configures the custom UDP probe transmit timers.
Step 7	port port Example: Router(config-slb-probe)# port 8	Configures the port to which the custom UDP probe is to connect.
Step 8	request data {start-byte \| continue} hex-data-string Example: Router(config-slb-probe)# request data 0 05 04 00 77 18 2A D6 CD 0A AD 53 4D F1 29 29 CF C1 96 59 CB	Defines the payload of the UDP request packet to be sent by a custom UDP probe.
Step 9	response clause-number data start-byte hex-data-string Example: Router(config-slb-probe)# response 2 data 44 DD DD	Defines the data string to match against custom UDP probe response packets.
Step 10	timeout seconds Example: Router(config-slb-probe)# timeout 20	(Optional) Sets a timeout for custom UDP probes.

How to Configure a DNS Probe

Perform the following task to configure a Domain Name System (DNS) probe.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb probe probe dns

4. address [ip-address [routed]]

5. faildetect number-of-probes

6. interval seconds

7. lookup ip-address

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip slb probe probe dns Example: Router(config)# ip slb probe PROBE4 dns	Configures the IOS SLB probe name and enters Domain Name System (DNS) probe configuration mode.
Step 4	address [ip-address [routed]] Example: Router(config-slb-probe)# address 10.1.10.1	(Optional) Configures an IP address to which to send the DNS probe.
Step 5	faildetect number-of-probes Example: Router(config-slb-probe)# faildetect 16	(Optional) Specifies the number of consecutive unacknowledged DNS probes that constitute failure of the real server or firewall.
Step 6	interval seconds Example: Router(config-slb-probe)# interval 11	(Optional) Configures the DNS probe transmit timers.
Step 7	lookup ip-address Example: Router(config-slb-probe)# lookup 10.1.10.1	(Optional) Configures an IP address of a real server that a DNS server should supply in response to a domain name resolve request.

How to Configure an HTTP Probe

Perform the following task to configure an HTTP probe.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb probe probe http

4. address [ip-address [routed]]

5. credentials {username [password]}

6. expect [status status-code] [regex expression]

7. header field-name [field-value]

8. interval seconds

9. port port

10. request [method {get | post | head | name name}] [url path]

11. Configure a route to the virtual server.

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip slb probe probe http Example: Router(config)# ip slb probe PROBE2 http	Configures the IOS SLB probe name and enters HTTP probe configuration mode.
Step 4	address [ip-address [routed]] Example: Router(config-slb-probe)# address 10.1.10.1	(Optional) Configures an IP address to which to send the HTTP probe.
Step 5	credentials {username [password]} Example: Router(config-slb-probe)# credentials Username1 password	(Optional) Configures header values for the HTTP probe.
Step 6	expect [status status-code] [regex expression] Example: Router(config-slb-probe)# expect status 401 regex Copyright	(Optional) Configures the expected HTTP status code or regular expression.
Step 7	header field-name [field-value] Example: Router(config-slb-probe)# header HeaderName HeaderValue	(Optional) Configures header values for the HTTP probe.
Step 8	interval seconds Example: Router(config-slb-probe)# interval 11	(Optional) Configures the HTTP probe transmit timers.
Step 9	port port Example: Router(config-slb-probe)# port 8	(Optional) Configures the port to which the HTTP probe is to connect.
Step 10	request [method {get \| post \| head \| name name}] [url path] Example: Router(config-slb-probe)# request method post url /probe.cgi?all	(Optional) Configures the URL path to request from the server, and the method used to perform the request to the server.
Step 11	Configure a route to the virtual server.	HTTP probes require a route to the virtual server. The route is not used, but it must exist to enable the socket code to verify that the destination can be reached, which in turn is essential for HTTP probes to function correctly. The route can be either: Host route--Advertised by the virtual server Default route--Specified using the ip route 0.0.0.0 0.0.0.0command, for example

How to Configure a Ping Probe

Perform the following task to configure a ping probe.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb probe probe ping

4. address [ip-address [routed]]

5. faildetect number-of-pings

6. interval seconds

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip slb probe probe ping Example: Router(config)# ip slb probe PROBE1 ping	Configures the IOS SLB probe name and enters ping probe configuration mode.
Step 4	address [ip-address [routed]] Example: Router(config-slb-probe)# address 10.1.10.1	(Optional) Configures an IP address to which to send the ping probe.
Step 5	faildetect number-of-pings Example: Router(config-slb-probe)# faildetect 16	(Optional) Specifies the number of consecutive unacknowledged pings that constitute failure of the real server or firewall.
Step 6	interval seconds Example: Router(config-slb-probe)# interval 11	(Optional) Configures the ping probe transmit timers.

How to Configure a TCP Probe

Perform the following task to configure a TCP probe.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb probe probe tcp

4. address [ip-address [routed]]

5. interval seconds

6. port port

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip slb probe probe tcp Example: Router(config)# ip slb probe PROBE5 tcp	Configures the IOS SLB probe name and enters TCP probe configuration mode.
Step 4	address [ip-address [routed]] Example: Router(config-slb-probe)# address 10.1.10.1	(Optional) Configures an IP address to which to send the TCP probe.
Step 5	interval seconds Example: Router(config-slb-probe)# interval 5	(Optional) Configures the TCP probe transmit timers.
Step 6	port port Example: Router(config-slb-probe)# port 8	Configures the port to which the TCP probe is to connect.

How to Configure a WSP Probe

Perform the following task to configure a Wireless Session Protocol (WSP) probe.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb probe probe wsp

4. address [ip-address [routed]]

5. interval seconds

6. url [path]

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip slb probe probe wsp Example: Router(config)# ip slb probe PROBE3 wsp	Configures the IOS SLB probe name and enters Wireless Session Protocol (WSP) probe configuration mode.
Step 4	address [ip-address [routed]] Example: Router(config-slb-probe)# address 10.1.10.1	(Optional) Configures an IP address to which to send the WSP probe.
Step 5	interval seconds Example: Router(config-slb-probe)# interval 11	(Optional) Configures the WSP probe transmit timers.
Step 6	url [path] Example: Router(config-slb-probe)# url http://localhost/test.txt	(Optional) Configures the WSP probe URL path.

How to Associate a Probe

Perform the following task to associate a probe with a real server or firewall.

After configuring a probe, you must associate the probe with a real server or firewall using the probe command. See "How to Configure a Server Farm and a Real Server" and "How to Configure Firewall Load Balancing" for more details.

Note

You cannot associate a WSP probe with a firewall.

SUMMARY STEPS

1. enable

2. configure terminal

3. Do one of the following:

ip slb firewallfarm firewall-farm
ip slb serverfarm server-farm

4. Do one of the following:

probe probe

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	Do one of the following: ip slb firewallfarm firewall-farm ip slb serverfarm server-farm Example: Router(config)# ip slb serverfarm PUBLIC Example: Router(config)# ip slb firewallfarm FIRE1	Identifies a firewall farm and enters firewall farm configuration mode. or Identifies a server farm and enters SLB server farm configuration mode.
Step 4	Do one of the following: probe probe Example: Router(config-slb-sfarm)# probe PROBE1 Example: Router(config-slb-fw-real)# probe FireProbe	Associates a probe with a firewall farm or a server farm.

How to Verify a Probe

Perform the following optional task to verify a probe.

To verify that a probe is configured correctly, use the show ip slb probecommand:

Router# show ip slb probe
Server:Port            State        Outages  Current  Cumulative
----------------------------------------------------------------
10.1.1.1:80            OPERATIONAL        0  never    00:00:00
10.1.1.2:80            OPERATIONAL        0  never    00:00:00
10.1.1.3:80            OPERATIONAL        0  never    00:00:00

How to Configure DFP

Perform the following task to configure IOS SLB as a Dynamic Feedback Protocol (DFP) manager, and to identify a DFP agent with which IOS SLB can initiate connections.

You can define IOS SLB as a DFP manager, as a DFP agent for another DFP manager, or as both at the same time. Depending on your network configuration, you might enter the commands for configuring IOS SLB as a DFP manager and the commands for configuring IOS SLB as a DFP agent on the same device or on different devices.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb dfp [password[[encrypt] secret-string [timeout]]

4. agent ip-address port [timeout[retry-count [retry-interval]]]

5. Configure IOS SLB as a DFP agent.

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip slb dfp [password[[encrypt] secret-string [timeout]] Example: Router(config)# ip slb dfp password Password1 360	Configures Dynamic Feedback Protocol (DFP), supplies an optional password, and enters DFP configuration mode.
Step 4	agent ip-address port [timeout[retry-count [retry-interval]]] Example: Router(config-slb-dfp)# agent 10.1.1.1 2221 30 0 10	Identifies a DFP agent to which IOS SLB can connect.
Step 5	Configure IOS SLB as a DFP agent.	To configure IOS SLB as a DFP agent, refer to the DFP Agent Subsystem feature document for Cisco IOS Release 12.2(18)SXB.

GPRS Load Balancing Configuration Task List

Perform the following tasks to configure general packet radio service (GPRS) load balancing.

SUMMARY STEPS

1. Configure a server farm and a real server.

2. Configure a virtual server.

3. Configure the virtual IP address as a loopback on each of the GGSNs in the servers.

4. Route each GGSN to each associated SGSN.

5. Route each SGSN to the virtual templates on each associated Cisco GGSN, and to the GPRS load-balancing virtual server.

6. Configure a GSN idle timer.

DETAILED STEPS

	Command or Action	Purpose
Step 1	Configure a server farm and a real server.	See "How to Configure a Server Farm and a Real Server". When you configure the server farm and real server for GPRS load balancing, keep the following considerations in mind: If GTP cause code inspection: Is not enabled--Accept the default setting (the weighted round robin algorithm) for the predictor command. Is enabled--Specify either the weighted round robin (roundrobin) or the weighted least connections (leastconns) algorithm. Specify the IP addresses (virtual template addresses for Cisco GGSNs) of the real servers performing the GGSN function, using the real command. Specify a reassign threshold less than the SGSN's N3-REQUESTS counter value using the reassign command. To enable dual-stack support for GTP load balancing: Specify the real server's IPv6 address using the realcommand.
Step 2	Configure a virtual server.	See "How to Configure a Virtual Server". When you configure the virtual command, keep the following considerations in mind: Specify a virtual GGSN IP address as the virtual server, and specify the udp keyword option. To load-balance GTP v1 and GTP v2 sessions, specify port number 2123, if the GGSNs and SGSNs are in compliance with the ETSI standard, or specify port number 0 or any to configure an all-port virtual server (that is, a virtual server that accepts flows destined for all ports). To load-balance GTP v0 sessions, specify port number 3386, if the GGSNs and SGSNs are in compliance with the ETSI standard, or specify port number 0 or any to configure an all-port virtual server. To enable GPRS load balancing: Without GTP cause code inspection--Specify the service gtpkeyword option. In GPRS load balancing without GTP cause code inspection enabled, when you configure the idle timer using the idle command, specify an idle timer greater than the longest possible interval between PDP context requests on the SGSN. With GTP cause code inspection--Specify the service gtp-inspectkeyword option. To enable dual-stack support for GTP load balancing: Specify the virtual server's IPv6 address and optional IPv6 prefix, using the virtual command. Associate the primary IPv6 server farm and optional backup IPv6 server farm with the virtual server, using the serverfarmcommand. Remove the client command from the configuration.
Step 3	Configure the virtual IP address as a loopback on each of the GGSNs in the servers.	(Required for dispatched mode) This step is required only if you are using dispatched mode without GTP cause code inspection enabled. Refer to the Cisco IOS Interface Configuration Guide "Configuring Virtual Interfaces" section for more information.
Step 4	Route each GGSN to each associated SGSN.	The route can be static or dynamic, but the GGSN needs to be able to reach the SGSN. Refer to the Cisco IOS Mobile Wireless Configuration Guide "Configuring Network Access to the GGSN" section for more details.
Step 5	Route each SGSN to the virtual templates on each associated Cisco GGSN, and to the GPRS load-balancing virtual server.	(Required) Refer to the configuration guide for your SGSN for more details.
Step 6	Configure a GSN idle timer.	(Optional) This step is applicable only if GTP cause code inspection is enabled. See "How to Configure a GSN Idle Timer" for more information.

How to Configure a GSN Idle Timer

How to Configure a GSN Idle Timer

Perform this task to configure a GPRS support node (GSN) idle timer.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb timers gtp gsn duration

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip slb timers gtp gsn duration Example: Router(config)# ip slb timers gtp gsn 45	Change the amount of time IOS SLB maintains sessions to and from an idle gateway GPRS support node (GGSN) or serving GPRS support node (SGSN).

GGSN-IOS SLB Messaging Task List

Perform this task to configure GGSN-IOS SLB messaging.

SUMMARY STEPS

1. Configure the GGSN to support GGSN-IOS SLB messaging.

2. Configure a server farm and a real server.

3. Configure a virtual server.

DETAILED STEPS

Command or Action

Purpose

Step 1

Configure the GGSN to support GGSN-IOS SLB messaging.

When you configure GGSN-IOS SLB messaging support, configure all IOS SLB virtual servers that share the same GGSN to use the same NAT mode, either dispatched mode or directed mode, using the gprs slb modecommand. The virtual servers cannot use a mix of dispatched mode and directed mode, because you can configure only one NAT mode on a given GGSN.

For more information, refer to the Cisco IOS Mobile Wireless Configuration Guide for GGSN Release 5.0 for Cisco IOS Release 12.3(2)XU or later.

Step 2

Configure a server farm and a real server.

See "How to Configure a Server Farm and a Real Server".

When you configure the server farm and real server for GGSN-IOS SLB messaging, to prevent IOS SLB from failing the current real server when reassigning the session to a new real server, disable automatic server failure detection by specifying the no faildetect inband command.

Step 3

Configure a virtual server.

See "How to Configure a Virtual Server".

When you configure the virtual server for GGSN-IOS SLB messaging, specify the gtp notification caccommand to limit the number of times IOS SLB can reassign a session to a new real server.

How to Configure GPRS Load Balancing Maps

Perform this task to configure GPRS load balancing maps.

GPRS load balancing maps enable IOS SLB to categorize and route user traffic based on access point names (APNs). To enable maps for GPRS load balancing, you must define a GPRS Tunneling Protocol (GTP) map, then associate the map with a server farm.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb map map-id gtp | radius}

4. apn string

5. exit

6. ip slb vserver virtual-server

7. virtual ipv4-address [ipv4-netmask[group]] [ipv6 ipv6-address [prefix ipv6-prefix]] {tcp| udp} [port| any] [service service]

8. serverfarm primary-farm [backup backup-farm[sticky]] [ipv6-primary ipv6-primary-farm[ipv6-backup ipv6-backup-farm]] [map map-id priority priority]

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode. If prompted, enter your password.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

ip slb map map-id gtp | radius}

Example:

Router(config)# ip slb map 1 radius

Configures an IOS SLB GTP map and enters SLB GTP map configuration mode.

Step 4

apn string

Example:

Router(config-slb-map-gtp)# apn abc

Configures an ASCII regular expression string to be matched against the access point name (APN) for general packet radio service (GPRS) load balancing.

Step 5

exit

Example:

Router(config-slb-map-gtp)# exit

Exits SLB GTP map configuration mode.

Step 6

ip slb vserver virtual-server

Example:

Router(config)# ip slb vserver GGSN_SERVER

Identifies a virtual server and enters virtual server configuration mode.

Step 7

virtual ipv4-address [ipv4-netmask[group]] [ipv6 ipv6-address [prefix ipv6-prefix]] {tcp| udp} [port| any] [service service]

Example:

Router(config-slb-vserver)# virtual 10.10.10.10 udp 0 service gtp

Specifies the virtual server IP address, type of connection, and optional TCP or User Datagram Protocol (UDP) port number, Internet Key Exchange (IKE) or Wireless Session Protocol (WSP) setting, and service coupling.

Note

For GPRS load balancing:

- Specify a virtual GGSN IP address as the virtual server, and specify the udp keyword option.
- To load-balance GTP v1 and GTP v2 sessions, specify port number 2123, if the GGSNs and SGSNs are in compliance with the ETSI standard, or specify port number 0 or any to configure an all-port virtual server (that is, a virtual server that accepts flows destined for all ports).
- To load-balance GTP v0 sessions, specify port number 3386, if the GGSNs and SGSNs are in compliance with the ETSI standard, or specify port number 0 or anyto configure an all-port virtual server.
- To enable GPRS load balancing without GTP cause code inspection, specify the service gtpkeyword option.
- To enable GPRS load balancing with GTP cause code inspection, specify the service gtp-inspectkeyword option.
- For dual-stack support for GTP load balancing, specify the virtual server's IPv4 and IPv6 addresses and optional IPv6 prefix.

Step 8

serverfarm primary-farm [backup backup-farm[sticky]] [ipv6-primary ipv6-primary-farm[ipv6-backup ipv6-backup-farm]] [map map-id priority priority]

Example:

Router(config-slb-vserver)# serverfarm farm1 backup farm2 map 1 priority 3

Associates a GTP map with a server farm. Associates a real server farm with a virtual server, and optionally configures a backup server farm and specifies that sticky connections are to be used in the backup server farm.

Note

For GPRS load balancing, if a real server is defined in two or more server farms, each server farm must be associated with a different virtual server.

You can associate more than one server farm with a virtual server by configuring more than one serverfarm command, each with a unique map ID and a unique priority. (That is, each map ID and each map priority must be unique across all server farms associated with the virtual server.)

If you are using GTP maps, and you have configured a real server in more than one server farm, you must associate a different virtual server with each server farm.

How to Configure KAL-AP Agent Support

Perform this task to configure KeepAlive Application Protocol (KAL-AP) agent support.

KAL-AP agent support enables IOS SLB to perform load balancing in a global server load balancing (GSLB) environment.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb capp udp

4. peer [ip-address] port port

5. peer [ip-address] secret [encrypt] secret-string

6. exit

7. ip slb serverfarm server-farm

8. kal-ap domain tag

9. farm-weight setting

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip slb capp udp Example: Router(config)# ip slb capp udp	Enables the KAL-AP agent and enters SLB Content Application Peering Protocol (CAPP) configuration mode.
Step 4	peer [ip-address] port port Example: Router(config-slb-capp)# peer port 6000	(Optional) Specifies the port to which the KAL-AP agent is to connect.
Step 5	peer [ip-address] secret [encrypt] secret-string Example: Router(config-slb-capp)# peer secret SECRET_STRING	(Optional) Enables Message Digest Algorithm Version 5 (MD5) authentication for the KAL-AP agent.
Step 6	exit Example: Router(config-slb-map-gtp)# exit	Exits SLB CAPP configuration mode.
Step 7	ip slb serverfarm server-farm Example: Router(config)# ip slb serverfarm PUBLIC	Identifies a server farm and enters SLB server farm configuration mode.
Step 8	kal-ap domain tag Example: Router(config-slb-sfarm)# kal-ap domain chicago-com	(Optional) Enables the KAL-AP agent to look for a domain tag when reporting the load for a virtual server.
Step 9	farm-weight setting Example: Router(config-slb-sfarm)# farm-weight 16	(Optional) Specifies a weight to be used by the KAL-AP agent when calculating the load value for a server farm.

RADIUS Load Balancing Configuration Task List

Perform this task to configure RADIUS load balancing.

SUMMARY STEPS

1. Configure a server farm and a real server.

2. Configure a virtual server.

3. Configure a virtual server. (continued)

4. Enable IOS SLB to inspect packets for RADIUS framed-IP sticky routing.

5. Configure RADIUS load balancing maps.

6. Configure RADIUS load balancing accelerated data plane forwarding.

7. Increase the number of available MLS entries.

8. Configure a probe.

DETAILED STEPS

Command or Action

Purpose

Step 1

Configure a server farm and a real server.

See "How to Configure a Server Farm and a Real Server".

When you configure the server farm and real server for RADIUS load balancing, keep the following considerations in mind:

Accept the default setting (the weighted round robin algorithm) for the predictor command.
(Optional) To enable session-based failure detection, specify a value of 1 for the numclients keyword on the faildetect numconnscommand.
(Optional) To specify the maximum number of IOS SLB RADIUS and GTP sticky subscribers that can be assigned to an individual virtual server, use the maxclients command.

Step 2

Configure a virtual server.

See "How to Configure a Virtual Server".

When you configure the virtual server for RADIUS load balancing, keep the following considerations in mind:

Specify the service radiuskeyword option, using the virtual command.
(Optional) To enable framed-IP routing to inspect the ingress interface, specify the accessinterface route framed-ipcommand.

If you configure the accessinterface route framed-ipcommand, you must also configure the virtual command with the service radiuskeywords specified.

(Optional) To change the amount of time IOS SLB waits for an ACCT-START message from a new mobile IP foreign agent in the event of a foreign agent hand-off, configure a hand-off radiuscommand.
(Optional) To set a duration for RADIUS entries in the IOS SLB session database, configure an idle command with the radius request keywords specified.
(Optional) To set a duration for entries in the IOS SLB RADIUS framed-IP sticky database, configure an idle command with the radius framed-ip keywords specified.

Step 3

Configure a virtual server. (continued)

(Optional) To enable IOS SLB to create the IOS SLB RADIUS framed-IP sticky database and direct RADIUS requests and non-RADIUS flows from a subscriber to the same service gateway, specify the stickycommand with the radius framed-ipkeywords.

If you configure the sticky radius framed-ipcommand, you must also configure the virtual command with the service radiuskeywords specified.

(Optional) To enable IOS SLB to purge entries in the IOS SLB RADIUS framed-IP sticky database upon receipt of an Accounting On or Off message, specify the purge radius framed-ip acct on-off virtual serverconfiguration command.

To prevent IOS SLB from purging entries in the IOS SLB RADIUS framed-IP sticky database upon receipt of an Accounting On or Off message, specify the no purge radius framed-ip acct on-off virtual serverconfiguration command.

(Optional) To enable IOS SLB to purge entries in the IOS SLB RADIUS framed-IP sticky database upon receipt of an Accounting-Stop message, specify the purge radius framed-ip acct stop virtual serverconfiguration command.

To prevent IOS SLB from purging entries in the IOS SLB RADIUS framed-IP sticky database upon receipt of an Accounting-Stop message, specify the no purge radius framed-ip acct stop virtual serverconfiguration command.

(Optional--For CDMA2000 networks only) To enable IOS SLB to create the IOS SLB RADIUS calling-station-ID sticky database and direct RADIUS requests from a subscriber to the same service gateway based on the calling station ID, specify the stickycommand with the radius calling-station-idkeywords.

To enable IOS SLB to create the IOS SLB RADIUS username sticky database and direct RADIUS requests from a subscriber to the same service gateway based on the username, specify the stickycommand with the radius usernamekeywords.

If you configure the sticky radius calling-station-idcommand or the sticky radius usernamecommand, you must also configure the virtual command with the service radiuskeywords specified, and you must configure the sticky radius framed-ipcommand.

You cannot configure both the sticky radius calling-station-id command and the sticky radius username command on the same virtual server.

(Optional--For RADIUS load balancing accelerated data plane forwarding only) To configure a VSA correlation group for an authentication virtual server, and to specify whether IOS SLB is to create VSA correlation entries based on RADIUS calling station IDs or RADIUS usernames, configure the radius inject auth command.

To configure a timer for VSA correlation for an authentication virtual server, configure the radius inject auth timercommand.

To buffer VSAs for VSA correlation for an authentication virtual server, configure the radius inject auth vsacommand.

To configure a VSA correlation group for an accounting virtual server, and to enable Message Digest Algorithm Version 5 (MD5) authentication for VSA correlation, configure the radius inject acct command.

Step 4

Enable IOS SLB to inspect packets for RADIUS framed-IP sticky routing.

(Optional) See "How to Enable IOS SLB to Inspect Packets for RADIUS Framed-IP Sticky Routing".

Step 5

Configure RADIUS load balancing maps.

(Optional) See "How to Configure RADIUS Load Balancing Maps".

Step 6

Configure RADIUS load balancing accelerated data plane forwarding.

(Optional) See "How to Configure RADIUS Load Balancing Accelerated Data Plane Forwarding".

Step 7

Increase the number of available MLS entries.

(Optional) If you are running IOS SLB in dispatched mode on a Cisco Catalyst 6500 series switch with Cisco Supervisor Engine 2, you can improve performance by configuring the no mls netflow command. This command increases the number of MLS entries available for hardware switching of end-user flows.

Note

If you are using IOS features that use the hardware NetFlow table, such as microflow QoS, reflexive ACLs, TCP intercept, or Web Cache Redirect, do not configure the no mls netflow command.

For more information about configuring MLS NetFlow, refer to the Cisco Catalyst 6000 Family IOS Software Configuration Guide .

Step 8

Configure a probe.

See "How to Configure a Probe".

To verify the health of the server, configure a ping probe.

How to Enable IOS SLB to Inspect Packets for RADIUS Framed-IP Sticky Routing
How to Configure RADIUS Load Balancing Maps
How to Configure RADIUS Load Balancing Accelerated Data Plane Forwarding

How to Enable IOS SLB to Inspect Packets for RADIUS Framed-IP Sticky Routing

You can enable IOS SLB to inspect packets whose source IP addresses match a configured IP address and subnet mask. If the source IP address of an inspected packet matches an entry in the IOS SLB RADIUS framed-IP sticky database, IOS SLB uses that entry to route the packet. Otherwise, IOS routes the packet.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb route framed-ip deny | ip-address netmask framed-ip | inter-firewall

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip slb route framed-ip deny \| ip-address netmask framed-ip \| inter-firewall Example: Router(config)# ip slb route 10.10.10.1 255.255.255.255 framed-ip	Enables IOS SLB to route packets using the RADIUS framed-IP sticky database, or to route packets from one firewall real server back through another firewall real server.

How to Configure RADIUS Load Balancing Maps

RADIUS load balancing maps enable IOS SLB to categorize and route user traffic based on RADIUS calling station IDs and usernames. To enable maps for RADIUS load balancing, you must define a RADIUS map, then associate the map with a server farm.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb map map-id radius

4. calling-station-id string

5. username string

6. exit

7. ip slb vserver virtual-server

8. virtual ipv4-address [ipv4-netmask[group]] [ipv6 ipv6-address [prefix ipv6-prefix]] {tcp| udp} [port| any] [service service]

9. serverfarm primary-farm [backup backup-farm[sticky]] [ipv6-primary ipv6-primary-farm[ipv6-backup ipv6-backup-farm]] [map map-id priority priority]

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode. If prompted, enter your password.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

ip slb map map-id radius

Example:

Router(config)# ip slb map 1 radius

Configures an IOS SLB RADIUS map and enters SLB RADIUS map configuration mode.

Step 4

calling-station-id string

Example:

Router(config-slb-radius-map)# calling-station-id .919*

Configures an ASCII regular expression string to be matched against the calling station ID attribute for RADIUS load balancing.

Step 5

username string

Example:

Router(config-slb-map-radius)# )# username ...?525*

Configures an ASCII regular expression string to be matched against the username attribute for RADIUS load balancing.

Step 6

exit

Example:

Router(config-slb-map-gtp)# exit

Exits SLB RADIUS map configuration mode.

Step 7

ip slb vserver virtual-server

Example:

Router(config)# ip slb vserver GGSN_SERVER

Identifies a virtual server and enters virtual server configuration mode.

Step 8

virtual ipv4-address [ipv4-netmask[group]] [ipv6 ipv6-address [prefix ipv6-prefix]] {tcp| udp} [port| any] [service service]

Example:

Router(config-slb-vserver)# virtual 10.0.0.1 udp 0 service radius

Specifies the virtual server IP address, type of connection, and optional TCP or User Datagram Protocol (UDP) port number, Internet Key Exchange (IKE) or Wireless Session Protocol (WSP) setting, and service coupling.

Note

For RADIUS load balancing, specify the service radiuskeyword option.

Step 9

serverfarm primary-farm [backup backup-farm[sticky]] [ipv6-primary ipv6-primary-farm[ipv6-backup ipv6-backup-farm]] [map map-id priority priority]

Example:

Router(config-slb-vserver)# serverfarm SF1 backup SF2 map 1 priority 1

Associates a RADIUS map with a server farm. Associates a real server farm with a virtual server, and optionally configures a backup server farm and specifies that sticky connections are to be used in the backup server farm.

Note

RADIUS load balancing does not support the stickykeyword.

You can associate more than one server farm with a virtual server by configuring more than one serverfarm command, each with a unique map ID and a unique priority. (That is, each map ID and each map priority must be unique across all server farms associated with the virtual server.)

How to Configure RADIUS Load Balancing Accelerated Data Plane Forwarding

Perform this task to configure RADIUS load balancing accelerated data plane forwarding.

RADIUS load balancing accelerated data plane forwarding, also known as Turbo RADIUS load balancing, is a high-performance solution that uses basic policy-based routing (PBR) route maps to manage subscriber data-plane traffic in a Cisco Content Services Gateway (CSG) environment.

Before You Begin

Turbo RADIUS load balancing requires a server farm configured with predictor route-map on the accounting virtual server.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb serverfarm server-farm

4. predictor [roundrobin| leastconns| route-map mapname]

5. exit

6. ip slb vserver virtual-server

7. virtual ipv4-address [ipv4-netmask[group]] [ipv6 ipv6-address [prefix ipv6-prefix]] {tcp| udp} [port| any] [service service]

8. serverfarm primary-farm [backup backup-farm[sticky]] [ipv6-primary ipv6-primary-farm[ipv6-backup ipv6-backup-farm]] [map map-id priority priority]

9. radius acct local-ack key [encrypt] secret-string

10. radius inject auth group-number {calling-station-id| username}

11. radius inject auth timer seconds

12. radius inject auth vsa vendor-id

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode. If prompted, enter your password.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

ip slb serverfarm server-farm

Example:

Router(config)# ip slb serverfarm PUBLIC

Identifies a server farm and enters SLB server farm configuration mode.

Step 4

predictor [roundrobin| leastconns| route-map mapname]

Example:

Router(config-slb-sfarm)# predictor route-map map1

(Optional) Specifies the algorithm to be used to determine how a real server is selected.

Turbo RADIUS load balancing requires the route-map keyword and mapname argument.

When you specify the predictor route-map command, no further commands in SLB server farm configuration mode or real server configuration mode are allowed.

Step 5

exit

Example:

Router(config-slb-sfarm)# exit

Exits SLB server farm configuration mode.

Step 6

ip slb vserver virtual-server

Example:

Router(config)# ip slb vserver RADIUS_AUTH

Identifies a virtual server and enters virtual server configuration mode.

Step 7

virtual ipv4-address [ipv4-netmask[group]] [ipv6 ipv6-address [prefix ipv6-prefix]] {tcp| udp} [port| any] [service service]

Example:

Router(config-slb-vserver)# virtual 10.10.10.10 udp 1813 service radius

Specifies the virtual server IP address, type of connection, and optional TCP or User Datagram Protocol (UDP) port number, Internet Key Exchange (IKE) or Wireless Session Protocol (WSP) setting, and service coupling and enters SLB virtual server configuration mode.

Note

For RADIUS load balancing, specify the service radiuskeyword option.

Step 8

serverfarm primary-farm [backup backup-farm[sticky]] [ipv6-primary ipv6-primary-farm[ipv6-backup ipv6-backup-farm]] [map map-id priority priority]

Example:

Router(config-slb-vserver)# serverfarm AAAFARM

Associates a RADIUS map with a server farm. Associates a real server farm with a virtual server, and optionally configures a backup server farm and specifies that sticky connections are to be used in the backup server farm.

Note

RADIUS load balancing does not support the stickykeyword.

You can associate more than one server farm with a virtual server by configuring more than one serverfarm command, each with a unique map ID and a unique priority. (That is, each map ID and each map priority must be unique across all server farms associated with the virtual server.)

Step 9

radius acct local-ack key [encrypt] secret-string

Example:

Router(config-slb-vserver)# radius acct local-ack key SECRET_PASSWORD

(Optional) Configures VSA correlation and enables a RADIUS virtual server to acknowledge RADIUS accounting messages

Note

If vendor-specific attribute (VSA) correlation is configured, and if the Cisco VSA is buffered, then the Cisco VSA is injected into the RADIUS Accounting-Start packet. Turbo RADIUS load balancing does not require VSA correlation.

This command is valid only for VSA correlation accounting virtual servers.

Step 10

radius inject auth group-number {calling-station-id| username}

Example:

Router(config-slb-vserver)# radius inject auth 1 calling-station-id

(Optional) Configures a VSA correlation group for an IOS SLB RADIUS load balancing accelerated data plane forwarding authentication virtual server, and specifies whether IOS SLB is to create VSA correlation entries based on RADIUS calling station IDs or RADIUS usernames.

For a given authentication virtual server, you can configure one radius inject authgroup-number calling-station-id command or one radius inject authgroup-number usernamecommand, but not both.

This command is valid only for VSA correlation authentication virtual servers.

Step 11

radius inject auth timer seconds

Example:

Router(config-slb-vserver)# radius inject auth timer 45

(Optional) Configures a timer for VSA correlation for an IOS SLB RADIUS load balancing accelerated data plane forwarding authentication virtual server.

This command is valid only for VSA correlation authentication virtual servers.

Step 12

radius inject auth vsa vendor-id

Example:

Router(config-slb-vserver)# radius inject auth vsa vendor1

(Optional) Buffers VSAs for VSA correlation for an IOS SLB RADIUS load balancing accelerated data plane forwarding authentication virtual server.

This command is valid only for VSA correlation authentication virtual servers.

Exchange Director for mSEF Configuration Task List

Perform this task to configure Exchange Director for mobile Service Exchange Framework (mSEF).

RADIUS Configuration for the Exchange Director
Firewall Configuration for the Exchange Director

RADIUS Configuration for the Exchange Director

Perform this task to configure RADIUS load balancing for the Exchange Director.

SUMMARY STEPS

1. Configure a server farm and a real server.

2. Configure a virtual server.

3. Configure a virtual server. (continued)

4. Enable IOS SLB to inspect packets for RADIUS framed-IP sticky routing.

5. Configure RADIUS load balancing maps.

6. Increase the number of available MLS entries.

7. Configure a probe.

DETAILED STEPS

	Command or Action	Purpose
Step 1	Configure a server farm and a real server.	See "How to Configure a Server Farm and a Real Server". When you configure the server farm and real server for RADIUS for the Exchange Director, keep the following considerations in mind: (Optional) Specify a value of 1 for the numclients keyword on the faildetect numconnscommand, if you want to enable session-based failure detection. (Optional) To specify the maximum number of IOS SLB RADIUS and GTP sticky subscribers that can be assigned to an individual virtual server, use the maxclients command.
Step 2	Configure a virtual server.	See "How to Configure a Virtual Server". When you configure the virtual server for RADIUS for the Exchange Director, keep the following considerations in mind: Specify the service radiuskeyword option, using the virtual command. (Optional) To enable framed-IP routing to inspect the ingress interface, specify the accessinterface route framed-ipcommand. If you configure the accessinterface route framed-ipcommand, you must also configure the virtual command with the service radiuskeywords specified. (Optional) To change the amount of time IOS SLB waits for an ACCT-START message from a new Mobile IP foreign agent in the event of a foreign agent hand-off, configure a hand-off radiuscommand. (Optional) To set a duration for RADIUS entries in the IOS SLB session database, configure an idle command with the radius request keywords specified. (Optional) To set a duration for entries in the IOS SLB RADIUS framed-IP sticky database, configure an idle command with the radius framed-ip keywords specified. (Optional) To enable IOS SLB to create the IOS SLB RADIUS framed-IP sticky database and direct RADIUS requests and non-RADIUS flows from a subscriber to the same service gateway, specify the stickycommand with the radius framed-ipkeywords. If you configure the sticky radius framed-ipcommand, you must also configure the virtual command with the service radiuskeywords specified.
Step 3	Configure a virtual server. (continued)	(Optional--for CDMA2000 networks only) To enable IOS SLB to create the IOS SLB RADIUS calling-station-ID sticky database and direct RADIUS requests from a subscriber to the same service gateway based on the calling station ID, specify the stickycommand with the radius calling-station-idkeywords. To enable IOS SLB to create the IOS SLB RADIUS username sticky database and direct RADIUS requests from a subscriber to the same service gateway based on the username, specify the stickycommand with the radius usernamekeywords. If you configure the sticky radius calling-station-idcommand or the sticky radius usernamecommand, you must also configure the virtual command with the service radiuskeywords specified, and you must configure the sticky radius framed-ipcommand. You cannot configure both the sticky radius calling-station-id command and the sticky radius username command on the same virtual server.
Step 4	Enable IOS SLB to inspect packets for RADIUS framed-IP sticky routing.	(Optional) See "How to Enable IOS SLB to Inspect Packets for RADIUS Framed-IP Sticky Routing".
Step 5	Configure RADIUS load balancing maps.	(Optional) See "How to Configure RADIUS Load Balancing Maps".
Step 6	Increase the number of available MLS entries.	(Optional
Step 7	Configure a probe.	See "How to Configure a Probe". To verify the health of the server, configure a ping probe.

Firewall Configuration for the Exchange Director

Perform this task to configure firewall load balancing for the Exchange Director.

This section lists the tasks used to configure firewalls for the Exchange Director. Detailed configuration information is contained in the referenced sections of this or other documents. Required and optional tasks are indicated.

How to Configure a Firewall Farm
How to Verify a Firewall Farm
How to Verify Firewall Connectivity
How to Configure a Probe
How to Configure a Wildcard Search
How to Configure Protocol-Level Purging of MLS entries
How to Configure Connection Purge Request Behavior
How to Configure Sticky Connection Purge Request Behavior

How to Configure a Firewall Farm

Perform the following required task to configure a firewall farm.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb firewallfarm firewall-farm

4. real ip-address

5. probe probe

6. weight setting

7. inservice

8. exit

9. access [source source-ip netmask] [destination destination-ip netmask]| inbound inbound-interface | outbound outbound-interface]

10. predictor hash address [port]

11. purge connection

12. purge sticky

13. replicate casa listen-ip remote-ip port [interval] [password [[encrypt] secret-string [timeout]]]

14. protocol tcp

15. delay duration

16. idle duration

17. maxconns maximum-number

18. sticky seconds [netmask netmask] [source| destination]

19. exit

20. protocol datagram

21. idle duration

22. maxconns maximum-number

23. sticky seconds [netmask netmask] [source| destination]

24. exit

25. inservice

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip slb firewallfarm firewall-farm Example: Router(config)# ip slb firewallfarm FIRE1	Adds a firewall farm definition to the IOS SLB configuration and enters firewall farm configuration mode.
Step 4	real ip-address Example: Router(config-slb-fw)# real 10.1.1.1	Identifies a firewall by IP address as a member of a firewall farm and enters real server configuration mode.
Step 5	probe probe Example: Router(config-slb-fw-real)# probe FireProbe	Associates a probe with the firewall.
Step 6	weight setting Example: Router(config-slb-fw-real)# weight 16	(Optional) Specifies the firewall's workload capacity relative to other firewalls in the firewall farm.
Step 7	inservice Example: Router(config-slb-fw-real)# inservice	Enables the firewall for use by the firewall farm and by IOS SLB.
Step 8	exit Example: Router(config-slb-fw-real)# exit	Exits real server configuration mode.
Step 9	access [source source-ip netmask] [destination destination-ip netmask]\| inbound inbound-interface \| outbound outbound-interface] Example: Router(config-slb-fw)# access destination 10.1.6.0 255.255.255.0	(Optional) Routes specific flows to a firewall farm.
Step 10	predictor hash address [port] Example: Router(config-slb-fw)# predictor hash address	(Optional) Specifies whether the source and destination TCP or User Datagram Protocol (UDP) port numbers, in addition to the source and destination IP addresses, are to be used when selecting a firewall.
Step 11	purge connection Example: Router(config-slb-fw)# purge connection	(Optional) Enables IOS SLB firewall load balancing to send purge requests for connections.
Step 12	purge sticky Example: Router(config-slb-fw)# purge sticky	(Optional) Enables IOS SLB firewall load balancing to send purge requests when the sticky idle timer expires.
Step 13	replicate casa listen-ip remote-ip port [interval] [password [[encrypt] secret-string [timeout]]] Example: Router(config-slb-fw)# replicate casa 10.10.10.11 10.10.11.12 4231	(Optional) Configures a stateful backup of IOS SLB firewall load balancing decision tables to a backup switch.
Step 14	protocol tcp Example: Router(config-slb-fw)# protocol tcp	(Optional) Enters firewall farm TCP protocol configuration mode.
Step 15	delay duration Example: Router(config-slb-fw-tcp)# delay 30	(Optional) For firewall farm TCP protocol configuration mode, specifies the time IOS SLB firewall load balancing maintains TCP connection context after a connection has ended.
Step 16	idle duration Example: Router(config-slb-fw-tcp)# idle 120	(Optional) For firewall farm TCP protocol configuration mode, specifies the minimum time IOS SLB firewall load balancing maintains connection context in the absence of packet activity.
Step 17	maxconns maximum-number Example: Router(config-slb-fw-tcp)# maxconns 1000	(Optional) For firewall farm TCP protocol configuration mode, specifies the maximum number of active TCP connections allowed on the firewall farm at one time.
Step 18	sticky seconds [netmask netmask] [source\| destination] Example: Router(config-slb-fw-tcp)# sticky 60	(Optional) For firewall farm TCP protocol configuration mode, specifies that connections from the same IP address use the same firewall if either of the following conditions is met: As long as any connection between the same pair of IP addresses exists (source and destination sticky). For a period, defined by duration , after the last connection is destroyed.
Step 19	exit Example: Router(config-slb-fw-tcp)# exit	Exits firewall farm TCP protocol configuration mode.
Step 20	protocol datagram Example: Router(config-slb-fw)# protocol datagram	(Optional) Enters firewall farm datagram protocol configuration mode.
Step 21	idle duration Example: Router(config-slb-fw-udp)# idle 120	(Optional) For firewall farm datagram protocol configuration mode, specifies the minimum time IOS SLB firewall load balancing maintains connection context in the absence of packet activity.
Step 22	maxconns maximum-number Example: Router(config-slb-fw-udp)# maxconns 1000	(Optional) For firewall farm datagram protocol configuration mode, specifies the maximum number of active datagram connections allowed on the firewall farm at one time.
Step 23	sticky seconds [netmask netmask] [source\| destination] Example: Router(config-slb-fw-udp)# sticky 60	(Optional) For firewall farm datagram protocol configuration mode, specifies that connections from the same IP address use the same firewall if either of the following conditions is met: As long as any connection between the same pair of IP addresses exists (source and destination sticky). For a period, defined by duration , after the last connection is destroyed.
Step 24	exit Example: Router(config-slb-fw-udp)# exit	Exits firewall farm datagram protocol configuration mode.
Step 25	inservice Example: Router(config-slb-fw)# inservice	Enables the firewall farm for use by IOS SLB.

How to Verify a Firewall Farm

Perform the following optional task to verify a firewall farm.

SUMMARY STEPS

1. The following show ip slb reals command displays the status of firewall farm FIRE1, the associated real servers, and their status:

2. The following show ip slb firewallfarmcommand displays the configuration and status of firewall farm FIRE1:

DETAILED STEPS

Step 1

The following show ip slb reals command displays the status of firewall farm FIRE1, the associated real servers, and their status:

Example:

Router# show ip slb real
real                  farm name        weight   state          conns
--------------------------------------------------------------------
10.1.1.2              FIRE1            8        OPERATIONAL    0
10.1.2.2              FIRE1            8        OPERATIONAL    0

Step 2

The following show ip slb firewallfarmcommand displays the configuration and status of firewall farm FIRE1:

Example:

Router# show ip slb firewallfarm
firewall farm    hash        state         reals
------------------------------------------------
FIRE1            IPADDR      INSERVICE     2

How to Verify Firewall Connectivity

Perform the following optional task to verify firewall connectivity.

To verify that IOS SLB firewall load balancing is configured and operating correctly, perform the following steps:

SUMMARY STEPS

1. Ping the external real servers (the ones outside the firewall) from the IOS SLB firewall load-balancing device.

2. Ping the internal real servers (the ones inside the firewall) from the clients.

3. Use the show ip slb stats command to display information about the IOS SLB firewall load-balancing network status:

4. Use the show ip slb real detailcommand to display detailed information about the IOS SLB firewall load-balancing real server status:

5. Use the show ip slb connscommand to display information about active IOS SLB firewall load-balancing connections:

DETAILED STEPS

Step 1	Ping the external real servers (the ones outside the firewall) from the IOS SLB firewall load-balancing device.
Step 2	Ping the internal real servers (the ones inside the firewall) from the clients.
Step 3	Use the show ip slb stats command to display information about the IOS SLB firewall load-balancing network status: Example: Router# show ip slb stats Pkts via normal switching: 0 Pkts via special switching: 0 Pkts dropped: 0 Connections Created: 1911871 Connections Established: 1967754 Connections Destroyed: 1313251 Connections Reassigned: 0 Zombie Count: 0 Connections Reused: 59752 Connection Flowcache Purges:1776582 Failed Connection Allocs: 17945 Failed Real Assignments: 0 Normal switching exists when IOS SLB packets are managed on normal IOS switching paths (CEF, fast switching, and process level switching). Special switching exists when IOS SLB packets are managed on hardware-assisted switching paths.
Step 4	Use the show ip slb real detailcommand to display detailed information about the IOS SLB firewall load-balancing real server status: Example: Router# show ip slb reals detail 172.16.88.5, SF1, state = OPERATIONAL, type = server ipv6 = 2342:2342:2343:FF04:2388:BB03:3223:8912 conns = 0, dummy_conns = 0, maxconns = 4294967295 weight = 8, weight(admin) = 8, metric = 0, remainder = 0 reassign = 3, retry = 60 failconn threshold = 8, failconn count = 0 failclient threshold = 2, failclient count = 0 total conns established = 0, total conn failures = 0 server failures = 0
Step 5	Use the show ip slb connscommand to display information about active IOS SLB firewall load-balancing connections: Example: Router# show ip slb conns vserver prot client real state nat ------------------------------------------------------------------------------- FirewallTCP TCP 80.80.50.187:40000 10.1.1.4 ESTAB none FirewallTCP TCP 80.80.50.187:40000 10.1.1.4 ESTAB none FirewallTCP TCP 80.80.50.187:40000 10.1.1.4 ESTAB none FirewallTCP TCP 80.80.50.187:40000 10.1.1.4 ESTAB none FirewallTCP TCP 80.80.50.187:40000 10.1.1.4 ESTAB none

What to Do Next

For additional commands used to verify IOS SLB networks and connections, see "How to Monitor and Maintain the Cisco IOS SLB Feature".

How to Configure a Probe

Perform the following required task to configure a probe.

The Exchange Director uses probes to detect and recover from failures. You must configure a probe on each real server in the firewall farm.

We recommend ping probes for each real server in a firewall farm. For more details, see "How to Configure a Ping Probe".
If a firewall does not allow ping probes to be forwarded, use HTTP probes instead. For more details, see "How to Configure an HTTP Probe".
You can configure more than one probe, in any combination of supported types (DNS, HTTP, TCP, or ping), for each firewall in a firewall farm.

How to Configure a Wildcard Search

How to Configure Protocol-Level Purging of MLS entries

To disable purge throttling on TCP and UDP flow packets, use the no form of this command.

How to Configure Connection Purge Request Behavior

To completely stop the sending of purge requests, use the no form of this command.

How to Configure Sticky Connection Purge Request Behavior

To completely stop the sending of purge requests for sticky connections, use the no form of this command.

VPN Server Load Balancing Configuration Task List

SUMMARY STEPS

1. Configure a server farm and a real server.

2. Configure a virtual server.

3. Configure a probe.

DETAILED STEPS

Command or Action

Purpose

Step 1

Configure a server farm and a real server.

See "How to Configure a Server Farm and a Real Server".

When you configure the server farm and real server for VPN server load balancing, specify the IP addresses of the real servers acting as VPN terminators using the real command.

Step 2

Configure a virtual server.

See "How to Configure a Virtual Server".

When you configure the virtual server for VPN server load balancing of IPSec flows, keep the following considerations in mind:

Configure a UDP virtual server using the virtual command with the protocol set to udp and the port set to isakmp. The isakmp keyword enables the cryptographic key exchange to occur through IKE (port 500).
Configure an ESP virtual server using the virtual command with the protocol set to esp.
Specify a sticky connection from the UDP virtual server to the ESP virtual server, and vice versa, using the sticky command with a duration of at least 15 seconds.

When you configure the virtual server for VPN server load balancing of Point-to-Point Tunneling Protocol (PPTP) flows, keep the following considerations in mind:

Configure a TCP virtual server, using the virtual command with the tcp keyword and port number 1723 specified.
Configure a GRE virtual server, using the virtual command with the gre keyword specified.
Specify a sticky connection from the TCP virtual server to the GRE virtual server, and vice versa, using the sticky command with a duration of at least 15 seconds.

Step 3

Configure a probe.

See "How to Configure a Probe".

To verify the health of the server, configure a ping probe.

ASN Load Balancing Configuration Task List

Perform the following task to configure load balancing across a set of Access Service Network (ASN) gateways.

SUMMARY STEPS

1. Configure the base station.

2. Configure a probe.

3. Associate a server farm and a real server with the probe.

4. Associate a virtual server with the server farm.

DETAILED STEPS

	Command or Action	Purpose
Step 1	Configure the base station.	To enable IOS SLB to manage requests from the Mobile Subscriber Station (MSS), configure the base station with the virtual IP address of the IOS SLB device.
Step 2	Configure a probe.	See "How to Configure a Probe". To verify the health of the server, configure a ping probe.
Step 3	Associate a server farm and a real server with the probe.	See "How to Configure a Server Farm and a Real Server". When you configure the server farm and real server for ASN load balancing, keep the following considerations in mind: Specify the IP addresses of the ASN gateways, using the real command. (Optional) Enable IOS SLB to automatically remove objects associated with failed real servers from the ASN sticky database, using the asn purge option on the real command.
Step 4	Associate a virtual server with the server farm.	See "How to Configure a Virtual Server". When you configure the virtual server for ASN load balancing, keep the following considerations in mind: Configure a virtual server, using the virtual command with the service set to asn. Configure an idle connection timer for ASN load balancing, using the idle command with the asn request keywords specified. (Optional) Enable IOS SLB to load-balance ASN sessions for a given MSID, using the asn msid option on the sticky command. (Optional) Configure a timer for the ASN MSID sticky database, using the idle command with the asn msid keywords specified. (Optional) Configure a Cisco BWG port, using the gw port command.

Home Agent Director Configuration Task List

Perform the following task to configure the Home Agent Director.

SUMMARY STEPS

1. Configure a server farm and a real server.

2. Configure a virtual server.

3. Configure the virtual IP address as a loopback on each of the home agents in the servers.

4. Configure DFP.

DETAILED STEPS

	Command or Action	Purpose
Step 1	Configure a server farm and a real server.	See "How to Configure a Server Farm and a Real Server". When you configure the server farm and real server for the Home Agent Director, keep the following considerations in mind: Accept the default setting (the weighted round robin algorithm) for the predictor command. Specify the IP addresses of the real servers acting as home agents, using the real command.
Step 2	Configure a virtual server.	See "How to Configure a Virtual Server". When you configure the virtual server for the Home Agent Director using the virtual command, keep the following considerations in mind: Specify the Home Agent Director's IP address as the virtual server. Specify the udp keyword option. Specify port number 434 if the home agents are in compliance with the IP Mobility Support, RFC 2002, or specify port number 0 or any to configure an all-port virtual server (that is, a virtual server that accepts flows destined for all ports). Specify the service ipmobilekeyword option.
Step 3	Configure the virtual IP address as a loopback on each of the home agents in the servers.	(Required for dispatched mode) This step is required only if you are using dispatched mode. Refer to the "Configuring a Loopback Interface" section in the Cisco IOS Interface Configuration Guide , Release 12.2 for more information.
Step 4	Configure DFP.	(Optional) See "How to Configure DFP". When you configure DFP for the Home Agent Director, keep the following considerations in mind: To control the maximum DFP weight sent by the home agent to IOS SLB, use the ip mobile home-agent dfp-max-weight command. To set the source address and home agent address field in the Registration Reply (RRP) as the real home agent's address, use the ip mobile home-agent dynamic-addresscommand. To set the maximum number of bindings, use the ip mobile home-agent max-binding command. For information about these Mobile IP commands, refer to the Cisco Mobile Wireless Home Agent Release 2.0 feature module.

How to Configure NAT

Perform the following task to configure the IOS SLB Network Address Translation (NAT) client address pool for client NAT.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb natpool pool start-ip end-ip [netmask netmask | prefix-length leading-1-bits] [entries init-address [max-address]]

4. nat {client pool | server}

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip slb natpool pool start-ip end-ip [netmask netmask \| prefix-length leading-1-bits] [entries init-address [max-address]] Example: Router(config)# ip slb natpool web-clients 10.1.10.1 10.1.10.5 netmask 255.255.0.0	Configures the client address pool. GPRS load balancing does not support this command. You do not need to configure the client address pool for server NAT.
Step 4	nat {client pool \| server} Example: Router(config-slb-sfarm)# nat server	Configures SLB NAT and specifies a NAT mode. All IPv4 or IPv6 server farms that are associated with the same virtual server must have the same NAT configuration.

What to Do Next

You must also specify either NAT client translation mode or NAT server address translation mode on the server farm, using the natcommand. See "How to Configure a Server Farm and a Real Server" for more details. When you configure the virtual server for NAT, remember that you cannot configure client NAT for an ESP or GRE virtual server.

How to Configure Static NAT

Perform the following task to configure static NAT.

Static NAT enables you to allow some users to use NAT and allow other users on the same Ethernet interface to continue with their own IP addresses. This option enables you to provide a default NAT behavior for real servers, differentiating between responses from a real server, and connection requests initiated by the real server.

Note

To avoid unexpected results, make sure your static NAT configuration mirrors your virtual server configuration.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb static {drop | nat {virtual | virtual-ip[per-packet | sticky]}}

4. real ip-address [port]

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode. If prompted, enter your password.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

ip slb static {drop | nat {virtual | virtual-ip[per-packet | sticky]}}

Example:

Router(config)# ip slb static nat 10.1.10.1 per-packet

Configures the real server's NAT behavior and enters static NAT configuration mode.

Note

If you specify the virtual-ip argument and you do not specify the per-packet option, IOS SLB uses server port translation to distinguish between connection requests initiated by different real servers.

Step 4

real ip-address [port]

Example:

Router(config-slb-static)# real 10.1.1.3

Configures one or more real servers to use static NAT.

Stateless Backup Configuration Task List

Perform the following task to configure stateless backup over VLANs between IOS SLB devices.

Note

For active standby, in which multiple IOS SLB devices share a virtual IP address, you must use exclusive client ranges and you must use policy routing to forward flows to the correct IOS SLB device.

SUMMARY STEPS

1. Configure required and optional IOS SLB functions.

2. Configure firewall load balancing.

3. Configure the IP routing protocol.

4. Configure the VLAN between the IOS SLB devices.

5. Verify the stateless backup configuration.

DETAILED STEPS

	Command or Action	Purpose
Step 1	Configure required and optional IOS SLB functions.	(Required for server load balancing) See "How to Configure Required and Optional IOS SLB Functions".
Step 2	Configure firewall load balancing.	(Required for firewall load balancing) See "How to Configure Firewall Load Balancing".
Step 3	Configure the IP routing protocol.	Refer to the "IP Routing Protocols" chapter of the Cisco IOS IP Configuration Guide, Release 12.2 for details.
Step 4	Configure the VLAN between the IOS SLB devices.	Refer to the "Virtual LANs" chapter of the Cisco IOS Switching Services Configuration Guide, Release 12.2 for details.
Step 5	Verify the stateless backup configuration.	(Optional) See "How to Verify the Stateless Backup Configuration".

How to Verify the Stateless Backup Configuration

How to Verify the Stateless Backup Configuration

Perform the following task to verify the stateless backup configuration.

For server load balancing, to verify that stateless backup has been configured and is operating correctly, use the following show ip slb vservers commands to display information about the IOS SLB virtual server status:

Router# show ip slb vservers
slb vserver      prot  virtual               state         conns   
-------------------------------------------------------------------
VS1              TCP   10.10.10.12:23        OPERATIONAL     2 
VS2              TCP   10.10.10.18:23        OPERATIONAL     2 
Router# show ip slb vservers detail
VS1, state = OPERATIONAL, v_index = 10
  virtual = 10.10.10.12:23, TCP, service = NONE, advertise = TRUE
  server farm = SERVERGROUP1, delay = 10, idle = 3600
  sticky timer = 0, sticky subnet = 255.255.255.255
  sticky group id = 0 
  synguard counter = 0, synguard period = 0
  conns = 0, total conns = 0, syns = 0, syn drops = 0
  standby group = None
VS2, state = INSERVICE, v_index = 11
  virtual = 10.10.10.18:23, TCP, service = NONE, advertise = TRUE
  server farm = SERVERGROUP2, delay = 10, idle = 3600
  sticky timer = 0, sticky subnet = 255.255.255.255
  sticky group id = 0 
  synguard counter = 0, synguard period = 0
  conns = 0, total conns = 0, syns = 0, syn drops = 0
  standby group = None

For firewall load balancing, to verify that stateless backup has been configured and is operating correctly, use the following show ip slb firewallfarmcommands to display information about the IOS SLB firewall farm status:

Router# show ip slb firewallfarm
 
firewall farm    hash        state         reals
------------------------------------------------
FIRE1            IPADDR      INSERVICE     2
Router# show ip slb firewallfarm details
FIRE1, hash = IPADDRPORT, state = INSERVICE, reals = 2
  FirewallTCP:
   sticky timer = 0, sticky subnet = 255.255.255.255
   idle = 3600, delay = 10, syns = 1965732, syn drop = 0 
   maxconns = 4294967295, conns = 597445, total conns = 1909512
  FirewallUDP:
   sticky timer = 0, sticky subnet = 255.255.255.255
   idle = 3600
   maxconns = 1, conns = 0, total conns = 1
  Real firewalls:
    10.1.1.3, weight = 10, OPERATIONAL, conns = 298823
    10.1.1.4, weight = 10, OPERATIONAL, conns = 298622
  Total connections = 597445

Stateful Backup of Redundant Route Processors Configuration Task List

SUMMARY STEPS

1. Configure the replication message rate for slave replication.

2. Configure required and optional IOS SLB functions.

3. Configure firewall load balancing.

DETAILED STEPS

Command or Action

Purpose

Step 1

Configure the replication message rate for slave replication.

Specify the ip slb replicate slave ratecommand in global configuration mode.

Step 2

Configure required and optional IOS SLB functions.

(Required for server load balancing) See "How to Configure Required and Optional IOS SLB Functions".

When you configure the virtual server for stateful backup of redundant route processors, keep the following considerations in mind:

Specify the replicate slavecommand.
(Optional) To set the replication delivery interval for the virtual server, configure a replicate intervalcommand.

Step 3

Configure firewall load balancing.

(Required for firewall load balancing) See "How to Configure Firewall Load Balancing".

When you configure the firewall farm for stateful backup of redundant route processors, keep the following considerations in mind:

Specify the replicate slavecommand.
(Optional) To set the replication delivery interval for the firewall farm, configure a replicate intervalcommand.

How to Configure Database Entries

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb entries [conn [init-conn [max-conn]] | frag [init-frag [max-frag] | lifetime timeout] | gtp {gsn [init-gsn[max-gsn] | nsapi [init-nsapi [max-nsapi]} | sticky [init-sticky [max-sticky]]]

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode. If prompted, enter your password.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

ip slb entries [conn [init-conn [max-conn]] | frag [init-frag [max-frag] | lifetime timeout] | gtp {gsn [init-gsn[max-gsn] | nsapi [init-nsapi [max-nsapi]} | sticky [init-sticky [max-sticky]]]

Example:

Router(config)# ip slb entries conn 128000 512000

Specifies an initial allocation and a maximum value for IOS SLB database entries.

Note

Enter this command before entering the rest of your IOS SLB configuration. If your IOS SLB configuration already exists, you must reload ISO SLB after entering this command.

How to Configure Buffers for the Fragment Database

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb maxbuffers frag buffers

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip slb maxbuffers frag buffers Example: Router(config)# ip slb maxbuffers frag 300	Configures the maximum number of buffers for the IOS SLB fragment database.

How to Clear Databases and Counters

SUMMARY STEPS

1. clear ip slb connections [firewallfarm firewall-farm| serverfarm server-farm| vserver virtual-server]

2. clear ip slb counters [kal-ap]

3. clear ip slb sessions [firewallfarm firewall-farm| serverfarm server-farm | vserver virtual-server]

4. clear ip slb sticky asn msid msid

5. clear ip slb sticky gtp imsi [id imsi]

6. clear ip slb sticky radius {calling-station-id [id string] | framed-ip [framed-ip [netmask]]}

DETAILED STEPS

	Command or Action	Purpose
Step 1	clear ip slb connections [firewallfarm firewall-farm\| serverfarm server-farm\| vserver virtual-server] Example: Router# clear ip slb connections vserver VSERVER1	Clears the IOS SLB connection database for one or more firewall farms, server farms, or virtual servers.
Step 2	clear ip slb counters [kal-ap] Example: Router# clear ip slb counters	Clears the IOS SLB counters. Use the kal-ap keyword to clear only IP IOS SLB KeepAlive Application Protocol (KAL-AP) counters.
Step 3	clear ip slb sessions [firewallfarm firewall-farm\| serverfarm server-farm \| vserver virtual-server] Example: Router# clear ip slb sessions serverfarm FARM1	Clears the IOS SLB RADIUS session database for one or more firewall farms, server farms, or virtual servers.
Step 4	clear ip slb sticky asn msid msid Example: Router# clear ip slb sticky asn msid 001646013fc0	Clears entries from an IOS SLB Access Service Network (ASN) Mobile Station ID (MSID) sticky database.
Step 5	clear ip slb sticky gtp imsi [id imsi] Example: Router# clear ip slb sticky gtp imsi	Clears entries from an IOS SLB general packet radio service (GPRS) Tunneling Protocol (GTP) International Mobile Subscriber ID (IMSI) sticky database.
Step 6	clear ip slb sticky radius {calling-station-id [id string] \| framed-ip [framed-ip [netmask]]} Example: Router# clear ip slb sticky radius framed-ip	Clears entries from an IOS SLB RADIUS sticky database.

How to Configure a Wildcard Search

SUMMARY STEPS

1. enable

2. configure terminal

3. Router(config)# mls ip slb search{wildcard [pfc | rp] | icmp}

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode. If prompted, enter your password.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

Router(config)# mls ip slb search{wildcard [pfc | rp] | icmp}

Example:

Router(config)# mls ip slb search wildcard rp

Specifies the behavior of IOS SLB wildcard searches.

This command is supported for Cisco Catalyst 6500 series switch only.

How to Configure Protocol-Level Purging of MLS Entries

SUMMARY STEPS

1. enable

2. configure terminal

3. Router(config)# mls ip slb purge global

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode. If prompted, enter your password.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

Router(config)# mls ip slb purge global

Example:

Router(config)# mls ip slb purge global

Specifies protocol-level purging of MLS entries from active TCP and UDP flow packets.

This command is supported for Cisco Catalyst 6500 series switches only.

How to Purge and Reassign Connections

You can enable IOS SLB to automatically remove connections to failed real servers and firewalls from the connection database even if the idle timers have not expired. This function is useful for applications that do not rotate the source port (such as IKE), and for protocols that do not have ports to differentiate flows (such as ESP).

You can also enable IOS SLB to automatically reassign to a new real server or firewall RADIUS sticky objects that are destined for a failed real server or firewall.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb serverfarm server-farm

4. failaction [purge | asn purge| gtp purge| radius reassign]

5. exit

6. ip slb firewallfarm firewall-farm

7. failaction purge

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. If prompted, enter your password.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip slb serverfarm server-farm Example: Router(config)# ip slb serverfarm PUBLIC	Enters server farm configuration mode.
Step 4	failaction [purge \| asn purge\| gtp purge\| radius reassign] Example: Router(config-slb-sfarm)# failaction purge	Configures IOS SLB behavior in the event that a real server fails.
Step 5	exit Example: Router(config-slb-sfarm)# exit	Exits server farm configuration mode.
Step 6	ip slb firewallfarm firewall-farm Example: Router(config)# ip slb firewallfarm fire1	Enters firewall farm configuration mode.
Step 7	failaction purge Example: Router(config-slb-fw)# failaction purge	Configures IOS SLB behavior in the event that a firewall fails.

How to Disable Automatic Server Failure Detection

If you have configured all-port virtual servers (that is, virtual servers that accept flows destined for all ports except GTP ports), flows can be passed to servers for which no application port exists. When the servers reject these flows, IOS SLB might fail the servers and remove them from load balancing. This situation can also occur in slow-to-respond AAA servers in RADIUS load-balancing environments. To prevent this situation, you can disable automatic server failure detection.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip slb serverfarm server-farm

4. real ipv4-address [ipv6 ipv6-address] [port]

5. no faildetect inband

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode. If prompted, enter your password.

Step 2

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

ip slb serverfarm server-farm

Example:

Router(config)# ip slb serverfarm PUBLIC

Enters server farm configuration mode.

Step 4

real ipv4-address [ipv6 ipv6-address] [port]

Example:

Router(config-slb-sfarm)# real 10.1.1.1

Identifies a real server as a member of a server farm and enters real server configuration mode.

Note

For dual-stack support for GTP load balancing, specify the real server's IPv4 and IPv6 address.

Step 5

no faildetect inband

Example:

Router(config-slb-real)# no faildetect inband

Disables automatic server failure detection.

Note

If you disable automatic server failure detection using the no faildetect inband command, We recommend that you configure one or more probes. If you specify the no faildetect inband command, the faildetect numconns command is ignored, if specified.

How to Monitor and Maintain the Cisco IOS SLB Feature

Perform the following task to obtain and display runtime information about IOS SLB.

SUMMARY STEPS

1. show ip slb conns [vserver virtual-server | client ip-address | firewall firewall-farm] [detail]

2. show ip slb dfp [agent agent-ip port | manager manager-ip | detail | weights]

3. show ip slb firewallfarm [detail]

4. show ip slb fragments

5. show ip slb gtp {gsn [gsn-ip-address] | nsapi [nsapi-key] [detail]

6. show ip slb map [map-id]

7. show ip slb natpool [name pool] [detail]

8. show ip slb probe [name probe] [detail]

9. show ip slb reals [sfarm server-farm] [detail]

10. show ip slb replicate

11. show ip slb serverfarms [name server-farm] [detail]

12. show ip slb sessions [asn| gtp[ipv6] | gtp-inspect| ipmobile| radius] [vserver virtual-server] [client ipv4-address netmask] [detail]

13. show ip slb static

14. show ip slb stats

15. show ip slb sticky [client ip-address netmask| radius calling-station-id[id string] | radius framed-ip[client ip-address netmask] | radius username[name string]]

16. show ip slb vservers [name virtual-server] [redirect] [detail]

17. show ip slb wildcard

DETAILED STEPS

Step 1	show ip slb conns [vserver virtual-server \| client ip-address \| firewall firewall-farm] [detail] Displays all connections managed by IOS SLB, or, optionally, only those connections associated with a particular virtual server or client. The following is sample output from this command: Example: Router# show ip slb conns vserver prot client real state ---------------------------------------------------------------------------- TEST TCP 10.150.72.183:328 10.80.90.25:80 INIT TEST TCP 10.250.167.226:423 10.80.90.26:80 INIT TEST TCP 10.234.60.239:317 10.80.90.26:80 ESTAB TEST TCP 10.110.233.96:747 10.80.90.26:80 ESTAB TEST TCP 10.162.0.201:770 10.80.90.30:80 CLOSING TEST TCP 10.22.225.219:995 10.80.90.26:80 CLOSING TEST TCP 10.2.170.148:169 10.80.90.30:80
Step 2	show ip slb dfp [agent agent-ip port \| manager manager-ip \| detail \| weights] Displays information about Dynamic Feedback Protocol (DFP) and DFP agents, and about the weights assigned to real servers. The following is sample output from this command: Example: Router# show ip slb dfp DFP Manager: Current passwd:NONE Pending passwd:NONE Passwd timeout:0 sec Agent IP Port Timeout Retry Count Interval -------------------------------------------------------------- 172.16.2.34 61936 0 0 180 (Default)
Step 3	show ip slb firewallfarm [detail] Displays information about firewall farms. The following is sample output from this command: Example: Router# show ip slb firewallfarm firewall farm hash state reals ------------------------------------------------ FIRE1 IPADDR OPERATIONAL 2
Step 4	show ip slb fragments Displays information from the IOS SLB fragment database. The following is sample output from this command: Example: Router# show ip slb fragments ip src id forward src nat dst nat --------------------------------------------------------------------- 10.11.2.128 12 10.11.2.128 10.11.11.11 10.11.2.128 10.11.2.128 13 10.11.2.128 10.11.11.11 10.11.2.128 10.11.2.128 14 10.11.2.128 10.11.11.11 10.11.2.128 10.11.2.128 15 10.11.2.128 10.11.11.11 10.11.2.128 10.11.2.128 16 10.11.2.128 10.11.11.11 10.11.2.128
Step 5	show ip slb gtp {gsn [gsn-ip-address] \| nsapi [nsapi-key] [detail] Displays IOS SLB GPRS Tunneling Protocol (GTP) information. The following is sample output from this command: Example: Router# show ip slb gtp gsn 10.0.0.0 type ip recovery-ie purging ------------------------------------------ SGSN 10.0.0.0 UNKNOWN N
Step 6	show ip slb map [map-id] Displays information about IOS SLB protocol maps. The following is sample output from this command: Example: Router# show ip slb map ID: 1, Service: GTP APN: Cisco.com, yahoo.com PLMN ID(s): 11122, 444353 SGSN access list: 100 ID: 2, Service: GTP PLMN ID(s): 67523, 345222 PDP Type: IPv4, PPP ID: 3, Service: GTP PDP Type: IPv6 ID: 4, Service: RADIUS Calling-station-id: "?919" ID: 5, Service: RADIUS Username: ". .778cisco."
Step 7	show ip slb natpool [name pool] [detail] Displays information about the IOS SLB NAT configuration. The following is sample output from this command: Example: Router# show ip slb natpool nat client B 209.165.200.225 1.1.1.6 1.1.1.8 Netmask 255.255.255.0 nat client A 10.1.1.1 1.1.1.5 Netmask 255.255.255.0
Step 8	show ip slb probe [name probe] [detail] Displays information about probes defined to IOS SLB. The following is sample output from this command: Example: Router# show ip slb probe Server:Port State Outages Current Cumulative ---------------------------------------------------------------- 10.10.4.1:0 OPERATIONAL 0 never 00:00:00 10.10.5.1:0 FAILED 1 00:00:06 00:00:06
Step 9	show ip slb reals [sfarm server-farm] [detail] Displays information about the real servers defined to IOS SLB. The following is sample output from this command: Example: Router# show ip slb reals real farm name weight state conns -------------------------------------------------------------------- 10.80.2.112 FRAG 8 OUTOFSERVICE 0 10.80.5.232 FRAG 8 OPERATIONAL 0 10.80.15.124 FRAG 8 OUTOFSERVICE 0 10.254.2.2 FRAG 8 OUTOFSERVICE 0 10.80.15.124 LINUX 8 OPERATIONAL 0 10.80.15.125 LINUX 8 OPERATIONAL 0 10.80.15.126 LINUX 8 OPERATIONAL 0 10.80.90.25 SRE 8 OPERATIONAL 220 10.80.90.26 SRE 8 OPERATIONAL 216 10.80.90.27 SRE 8 OPERATIONAL 216 10.80.90.28 SRE 8 TESTING 1 10.80.90.29 SRE 8 OPERATIONAL 221 10.80.90.30 SRE 8 OPERATIONAL 224 10.80.30.3 TEST 100 READY_TO_TEST 0 10.80.30.4 TEST 100 READY_TO_TEST 0 10.80.30.5 TEST 100 READY_TO_TEST 0 10.80.30.6 TEST 100 READY_TO_TEST 0
Step 10	show ip slb replicate Displays information about the IOS SLB replication configuration. The following is sample output from this command: Example: Router# show ip slb replicate VS1, state = NORMAL, interval = 10 Slave Replication: Enabled Slave Replication statistics: unsent conn updates: 0 conn updates received: 0 conn updates transmitted: 0 update messages received: 0 update messages transmitted: 0 Casa Replication: local = 10.1.1.1 remote = 10.2.2.2 port = 1024 current password = <none> pending password = <none> password timeout = 180 sec (Default) Casa Replication statistics: unsent conn updates: 0 conn updates received: 0 conn updates transmitted: 0 update packets received: 0 update packets transmitted: 0 failovers: 0
Step 11	show ip slb serverfarms [name server-farm] [detail] Displays information about the server farms defined to IOS SLB. The following is sample output from this command: Example: Router# show ip slb serverfarms server farm predictor reals bind id ------------------------------------------------- FRAG ROUNDROBIN 4 0 LINUX ROUNDROBIN 3 0 SRE ROUNDROBIN 6 0 TEST ROUNDROBIN 4 0
Step 12	show ip slb sessions [asn\| gtp[ipv6] \| gtp-inspect\| ipmobile\| radius] [vserver virtual-server] [client ipv4-address netmask] [detail] Displays information about sessions managed by IOS SLB. The following is sample output from this command: Example: Router# show ip slb sessions radius Source Dest Retry Addr/Port Addr/Port Id Count Real Vserver ------------------------------------------------------------------------------ 10.10.11.1/1645 10.10.11.2/1812 15 1 10.10.10.1 RADIUS_ACCT
Step 13	show ip slb static Displays information about the IOS SLB server Network Address Translation (NAT) configuration. The following is sample output from this command: Example: Router# show ip slb static real action address counter --------------------------------------------------------------- 10.11.3.4 drop 0.0.0.0 0 10.11.3.1 NAT 10.11.11.11 3 10.11.3.2 NAT sticky 10.11.11.12 0 10.11.3.3 NAT per-packet 10.11.11.13 0
Step 14	show ip slb stats Displays IOS SLB statistics. The following is sample output from this command: Example: Router# show ip slb stats Pkts via normal switching: 779 Pkts via special switching: 0 Pkts via slb routing: 0 Pkts Dropped: 4 Connections Created: 4 Connections Established: 4 Connections Destroyed: 4 Connections Reassigned: 5 Zombie Count: 0 Connections Reused: 0 Connection Flowcache Purges: 0 Failed Connection Allocs: 0 Failed Real Assignments: 0 RADIUS Framed-IP Sticky Count: 0 RADIUS username Sticky Count: 0 RADIUS calling-station-id Sticky Count: 0 GTP IMSI Sticky Count: 0 Failed Correlation Injects: 0 Pkt fragments drops in ssv: 0 ASN MSID sticky count: 1
Step 15	show ip slb sticky [client ip-address netmask\| radius calling-station-id[id string] \| radius framed-ip[client ip-address netmask] \| radius username[name string]] Displays information about the sticky connections defined to IOS SLB. The following is sample output from this command: Example: Router# show ip slb sticky client netmask group real conns ----------------------------------------------------------------------- 10.10.2.12 255.255.0.0 4097 10.10.3.2 1
Step 16	show ip slb vservers [name virtual-server] [redirect] [detail] Displays information about the virtual servers defined to IOS SLB. The following is sample output from this command: Example: Router# show ip slb vservers slb vserver prot virtual state conns --------------------------------------------------------------------- TEST TCP 10.80.254.3:80 OPERATIONAL 1013 TEST21 TCP 10.80.254.3:21 OUTOFSERVICE 0 TEST23 TCP 10.80.254.3:23 OUTOFSERVICE 0
Step 17	show ip slb wildcard Displays information about the wildcard representation for virtual servers defined to IOS SLB. The following is sample output from this command: Example: Router# show ip slb wildcard Interface Source Address Port Destination Address Port Prot ANY 0.0.0.0/0 0 3.3.3.3/32 2123 UDP ANY 0.0.0.0/0 0 3.3.3.3/32 0 UDP ANY 0.0.0.0/0 0 0.0.0.0/0 0 ICMP Interface: ANY Source Address [Port]: : :/0[0] Destination Address [Port]: 2342:2342:2343:FF04:2341:AA03:2323:8912/128[0] Protocol: ICMPV6 Interface: ANY Source Address [Port]: : :/0[0] Destination Address [Port]: 2342:2342:2343:FF04:2341:AA03:2323:8912/128[2123] Protocol: UDP