Cisco 7600 Series Router Software Configuration Guide, Cisco IOS Release 15S

Step 1

enable

Enables privileged EXEC mode.

• Enter your password if prompted.

Step 2

configure terminal

Router# configure terminal

Enters global configuration mode.

Step 3

ip slb serverfarm server-farm

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

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

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

Step 5

nat {client pool | server}

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.

Step 6

predictor [roundrobin | leastconns | route-map mapname]

Router(config-slb-sfarm)# predictor leastconns

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

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 functions only with the default setting (the weighted round robin algorithm).

When you use 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.

Step 7

probe probe

Router(config-slb-sfarm)# probe PROBE1

(Optional) Associates a probe with the real server.

Step 8

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

Router(config-slb-sfarm)# real 10.1.1.1 ipv6 100::10:10:10:1

Identifies a real server by IPv4 and IPv6 address and optional 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 GGSN) of the real servers performing the GGSN function.

Step 9

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

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 a single SGSN is configured in the 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 10

maxclients number-of-conns

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 11

maxconns number-of-conns [sticky-override]

Router(config-slb-real)# maxconns 1000

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

Step 12

reassign threshold

Router(config-slb-real)# reassign 2

(Optional) Specifies the threshold of consecutive unacknowledged synchronize sequence numbers (SYNs) or Create PDP requests that, if exceeded, result in an attempt to connect to a different real server.

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

Step 13

retry retry-value

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 14

weight setting

Router(config-slb-real)# weight 24

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

If Dynamic Feedback Protocol (DFP) is used, the static weights defined 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 15

inservice

Router(config-slb-real)# inservice

Enables the real server for use by IOS SLB.

Step 1

enable

Enables privileged EXEC mode.

• Enter your password if prompted.

Step 2

configure terminal

Router# configure terminal

Enters global configuration mode.

Step 3

ip slb vserver virtual-server

Router(config)# ip slb vserver PUBLIC_HTTP

Identifies a virtual server and enters virtual server configuration mode.

Step 4

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

Router(config-slb-vserver)# virtual 10.0.0.1 ipv6 100::100:1 udp 0 service gtp

Specifies the following:

• Virtual server IP address
• IPv6 address (including the type of connection)
• Optional TCP or User Datagram Protocol (UDP) port number,
• Internet Key Exchange (IKE) or Wireless Session Protocol (WSP) setting
• Service coupling.

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 (In this case, the virtual server 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.

Step 5

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

Router(config-slb-vserver)# serverfarm SF backup BACKUPSF ipv6-primary V6SF ipv6-backup BACKUPV6SF map 1 priority 1

Associates a real server farm with a virtual server, and optionally configures a backup server farm.

For GPRS load balancing, if the same 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 to a GTP virtual server by configuring more than one serverfarm command, each with a unique map ID and a unique priority.

Step 6

access interface [route framed-ip]

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

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

Step 7

advertise [active]

Router(config-slb-vserver)# advertise

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

Step 8

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

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

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

GPRS load balancing supports only the gtp carrier-code option only if the GTP cause code inspection is enabled.

Step 9

delay {duration | radius framed-ip duration}

Router(config-slb-vserver)# delay 30

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

Step 10

gtp notification cac [reassign-count]

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

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.

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

hand-off radius duration

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

(Optional) Changes the duration 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 13

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

Router(config-slb-vserver)# idle 120

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

Note For 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 14

replicate casa listen-ip remote-ip port [interval]

[password [encrypt] secret-string timeout]

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 gtp keyword on the virtual command, and you do not specify the sticky command with the gtp imsi keyword, the replicate casa command is not supported because sessions are not persistent, and there is nothing to replicate.

Step 15

replicate interval interval

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

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

The Home Agent Director does not support this command.

If you specify the service gtp keyword on the virtual command, and you do not specify the sticky command with the gtp imsi keyword, the replicate casa command is not supported because sessions are not persistent, and there is nothing to replicate.

Step 16

replicate slave

Router(config-slb-vserver)# replicate slave

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

The Home Agent Director does not support this command.

If you specify the service gtp keyword on the virtual command, and you do not specify the sticky command with the gtp imsi keyword, the replicate casa command is not supported because sessions are not persistent, and there is nothing to replicate.

Note If you use a Supervisor Engine with a configured replicate slave, you might receive out-of-sync messages on the Supervisor.

Step 17

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]}

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

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

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 18

synguard syn-count interval

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 19

inservice [standby group-name] [active]

Router(config-slb-vserver)# inservice

Enables the virtual server.