Table Of Contents

DistributedDirector Commands

alias (boomerang)

ip director cache size

ip director cache refresh

ip director cache time

ip director default priorities

ip director default weights

ip director dfp

ip director dfp security

ip director drp rttprobe

ip director drp synchronized

ip director host priority

ip director host weights

ip director server availability

ip director server port availability

ip dns server

ip drp domain

server (boomerang)

show ip director default

show ip director dfp

show ip drp boomerang

snmp-server enable traps director

ttl dns

ttl ip

DistributedDirector Commands

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This chapter describes the commands used to configure the Cisco DistributedDirector.

alias (boomerang)

To configure an alias name for a specified domain, use the alias command in boomerang configuration mode. To remove this command from the configuration file and restore the system to its default condition with respect to this command, use the no form of this command.

alias alias-name

no alias alias-name

Syntax Description

alias-name

Alias name for a specified domain.

Defaults

No default behavior or values.

Command Modes

Boomerang configuration

Command History

Release	Modification
12.2(8)T	This command was introduced.

Usage Guidelines

The alias command can be used only on a Director Response Protocol (DRP) agent. The boomerang client is the DRP agent.

Use the alias command to specify one or more alias names for an existing domain. Because the boomerang client maintains separate counters for requests received for each domain name (alias or otherwise), use the show ip drp boomerang command to view these counters for a specified domain name and each of its aliases.

Examples

In the following example, the domain name alias is configured for www.boom1.com. The new alias for www.boom1.com is www.boom2.com:

Router(config)# ip drp domain www.boom1.com

Router(config-boomerang)# alias www.boom2.com

Router# show running-config

.

.

.

ip drp domain www.boom1.com

alias www.boom2.com

Related Commands

Command	Description
ip drp domain	Adds a new domain to the DistributedDirector client or configures an existing domain and puts the client in boomerang configuration mode.
server (boomerang configuration)	Configures the server address for a specified boomerang domain.
show ip drp	Displays DRP statistics on DistributedDirector or a DRP server agent.
show ip drp boomerang	Displays boomerang information on the DRP agent.
ttl dns	Configures the number of seconds for which an answer received from the boomerang client will be cached by the DNS client.
ttl ip	Configures the IP TTL value for the boomerang response packets sent from the boomerang client to the DNS client in number of hops.

Related Commands

Command	Description
show cef state	Displays the state of CEF.

ip director cache size

To configure the variable size of the DistributedDirector cache, use the ip director cache size command in global configuration mode. To remove this command from the configuration file and restore the system to its default condition with respect to this command, use the no form of this command.

ip director cache size entries

no ip director cache size entries

Syntax Description

entries

Maximum number of cache entries. Range is from 1 to 4294967295.

Defaults

Maximum number of cache entries: 2000

Command Modes

Global configuration

Command History

Release	Modification
12.2(8)T	This command was introduced.

Usage Guidelines

Use the ip director cache size command to configure the maximum number of cache entries that the DistributedDirector system will retain in its cache. This cache size is the maximum number of cache entries that are displayed when the user enters the show ip director cache command.

Examples

The following example configures the maximum number of cache entries:

Router(config)# ip director cache size 1500

Cache size shrinked to 1500

Router# show ip director cache

Director cache is on

Cache current size = 0 maximum size = 1500

Cache time for sort cache entries: 60 secs

Director sort cache hits = 0

Related Commands

Command	Description
ip director cache	Enables the sorting cache on DistributedDirector.
ip director cache time	Configures how long the DistributedDirector system will retain per-client sorting information.

ip director cache refresh

To enable the DistributedDirector Cache Auto Refresh feature, use the ip director cache refresh command in global configuration mode. To disable automatic background refresh, use the no form of this command.

ip director cache refresh

no ip director cache refresh

Syntax Description

This command has no keywords or arguments.

Defaults

Automatic background refresh is disabled.

Command Modes

Global configuration

Command History

Release	Modification
12.2(8)T	This command was introduced.

Usage Guidelines

The sorting cache on DistributedDirector must be enabled before you can use the ip director cache refresh command. To enable the sorting cache, use the ip director cache command.

Once automatic background refresh for the DistributedDirector cache is enabled, the cache will actively and continuously update every expired entry by processing a fake Domain Name System (DNS) request. The cache accumulates and updates answers to all past DNS queries received since cache auto refresh was initiated. Any repeat DNS request is always serviced directly from the cache.

Examples

The following example enables automatic background refresh for the DistributedDirector cache:

Router(config)# ip director cache 

Router(config)# ip director cache refresh

Router# show running-config

ip host myhost 172.2.2.10 172.2.2.20 172.2.2.30 

.

.

.

ip director cache refresh

ip director cache time

To configure how long the DistributedDirector system will retain per-client sorting information, use the ip director cache time command in global configuration mode. To remove this command from the configuration file and restore the system to its default condition with respect to this command, use the no form of this command.

ip director cache time seconds

no ip director cache time seconds

Syntax Description

seconds

How long the per-client sorting information is retained, in number of seconds. Range is from 1 to 2147483.

Defaults

60 seconds

Command Modes

Global configuration

Command History

Release	Modification
12.2(8)T	This command was introduced.

Usage Guidelines

Use the ip director cache time command to specify how long the DistributedDirector system will retain per-client sorting in its cache. This cache time is the maximum amount of cache time displayed when the user enters the show ip director cache command.

Examples

The following example configures how long the DistributedDirector system will retain per-client sorting information:

Router(config)# ip director cache time 100

Router# show ip director cache

Director cache is on

Cache current size = 0 maximum size = 2000

Cache time for sort cache entries: 100 secs

Director sort cache hits = 0

Related Commands

Command	Description
ip director cache	Enables the sorting cache on DistributedDirector.
ip director cache size	Configures the variable size of the DistributedDirector cache.

ip director default priorities

To set a default priority for a specific metric on the DistributedDirector, use the ip director default priorities command in global configuration mode. To remove a default priority for a metric, use the no form of this command.

ip director default priorities [drp-int num] [drp-ext num] [drp-ser num] [random num] [admin num] [drp-rtt num] [portion num] [availability num] [route-map num] [boomerang num]

no ip director default priorities [drp-int num] [drp-ext num] [drp-ser num] [random num] [admin num] [drp-rtt num] [portion num] [availability num] [route-map num] [boomerang num]

Syntax Description

drp-int	(Optional) DRP internal metric. Range is from 1 to 100.
num	Numeric value of a priority level for a given metric.
drp-ext	(Optional) DRP external metric. Range is from 1 to 100.
drp-ser	(Optional) DRP server metric. Range is from 1 to 100.
random	(Optional) Random metric. Range is from 1 to 100.
admin	(Optional) Administrative metric. Range is from 1 to 100.
drp-rtt	(Optional) DRP round-trip time metric. Range is from 1 to 100.
portion	(Optional) Portion metric. Range is from 1 to 100.
availability	(Optional) Availability metric. Range is from 1 to 100.
route-map	(Optional) Route-map metric. Range is from 1 to 100.
boomerang	(Optional) Boomerang metric.

Defaults

No default priorities are specified.

Command Modes

Global configuration

Command History

Release	Modification
12.2(4)T	This command was introduced.
12.2(8)T	The boomerang metric was added.

Usage Guidelines

Not all of the metrics need to be specified, but at least one must be specified. If the boomerang metric is specified for a given host name, then all metrics of lower priority (that is, having a higher priority number) than boomerang are always ignored.

The default priorities specified will take effect if no priorities are specified in the ip director host priority command or in the corresponding Domain Name System (DNS) text record for the host.

To set the default priority for several metrics, enter the metric keywords and values to be configured on the same line as the ip director default priorities command.

Examples

In the following example, the boomerang metric is selected as the default priority:

Router(config)# ip director default priorities boomerang 1

Router# show running-config

ip host boom1 172.2.2.10 172.2.2.20 172.2.2.30 

ip director server 172.2.2.20 drp-association 172.4.4.2

ip director server 172.2.2.30 drp-association 172.4.4.3

ip director server 172.2.2.10 drp-association 172.4.4.1

ip director host boom1 

no ip director cache

ip dns primary boom1 soa boom1 boom1@com

ip director host boom1 priority boomerang 1

no ip director drp synchronized

Related Commands

Command	Description
ip director access-list	Defines an access list for DistributedDirector that specifies which subdomain names and host names should be sorted.
ip director cache	Enables the sorting cache on DistributedDirector.
ip director default priorities	Sets a default priority for a specific metric on DistributedDirector.
ip director default weights	Configures default weight metrics for DistributedDirector.
ip director host priority	Configures the order in which DistributedDirector considers metrics when picking a server.
ip director host weights	Sets host-specific weights for the metrics that DistributedDirector uses to determine the best server within a specific host name.
ip director server admin-pref	Configures a per-service administrative preference value.
ip director server portion	Sets the portion value for a specific server.
ip director server preference	Specifies DistributedDirector preference of one server over others or takes a server out of service.
show ip director default priority	Verifies the default configurations of DistributedDirector metrics.
show ip director default weights	Shows DistributedDirector default weights.
show ip director servers	Displays DistributedDirector server preference information.

ip director default weights

To configure default weight metrics for DistributedDirector, use the ip director default weights command in global configuration mode. To set the defaults to zero, use the no form of this command.

ip director default weights {[drp-int n] [drp-ext n] [drp-ser n] [drp-rtt n] [random n] [admin n] [portion n] [availability n] [route-map n]}

no ip director default weights {[drp-int n] [drp-ext n] [drp-ser n] [drp-rtt n] [random n] [admin n] [portion n] [availability n] [route-map n]}

Syntax Description

drp-int n	(Optional) Director Response Protocol (DRP) internal metric. The range is 1 to 100. This option sends a DRP request to all DRP server agents, asking them for the distance from themselves to the edge of their Border Gateway Protocol (BGP) autonomous system in the direction of the client originating the Domain Name System (DNS) query. This distance can be used along with the DRP external metric (drp-ext) to help determine the distance between the router and the client originating the DNS query. If the client and the DRP server agent are in the same autonomous system, this metric returns the Interior Gateway Protocol (IGP) cost metric between the client and the DRP server agent.
drp-ext n	(Optional) DRP external metric. The range is 1 to 100. This option sends a DRP request to all DRP server agents, asking them for the BGP distance between them and the client originating the DNS query. This distance represents the number of BGP hops between the autonomous system of the DRP server agent and the autonomous system of the client originating the DNS query. Because this is BGP information, the DRP server agents need to have access to full Internet BGP information in order for this metric to be useful.
drp-ser n	(Optional) DRP server metric. The range is 1 to 100. This option sends a DRP request to all DRP server agents, asking them for the IGP route metric between them and the distributed servers that they support. This distance can be used with the DRP internal metric (drp-int) to get a finer distance calculation between the distributed servers and the edge of the BGP autonomous system in the direction of the client originating the DistributedDirector query. If a true BGP border router is used as a DRP server agent, the DRP server metric will return the IGP route metric between the distributed server and the BGP border router (autonomous system edge). Because DRP server metrics should not change frequently, DistributedDirector issues DRP server queries (and caches the results) every 10 minutes.
drp-rtt n	(Optional) DRP round-trip time metric. The range is 1 to 100. This option sends a DRP request to all DRP server agents, asking them for the round-trip time between the DRP agent and the client originating the DNS query.
random n	(Optional) Random metric. The range is 1 to 100. This option selects a random number for each distributed server and defines the "best" server as the one with the smallest random number assignment. Using this metric alone results in random redirection of clients to the distributed servers. Because this metric requires no routing table information, it does not trigger DRP requests to the DRP server agents.
admin n	(Optional) Administrative metric. The range is 1 to 100. This option specifies a simple preference of one server over another. If the administrative metric has been explicitly set to zero, the Director will not consider the server, so the server is taken out of service.
portion n	(Optional) Portion metric. The range is 1 to 100. This option assigns a load "portion" to each server such that servers with a higher portion value will receive a larger percentage of connections at any one time.
availability n	(Optional) Availability metric. The range is 1 to 65,535. This option specifies the load information for the DistributedDirector. The default value is 65,535.
route-map n	(Optional) Route-map metric. The range is 1 to 100. This option specifies if a server should be offered to a client.

Defaults

No default weights are specified.

The availability default value is 65,535.

Command Modes

Global configuration

Command History

Release	Modification
11.1(18)IA	This command was introduced.
12.1(5)T	The availability and route-map metrics were added.
12.2(4)T3	The command name was changed slightly: default weights replaced default-weights. (DistributedDirector Enhancements for Cisco IOS Release 12.2(4)T3)

Usage Guidelines

Not all the metrics need to be configured; however, at least one metric must be configured when this command is used.

Default weights are used for all host names sorted by the DistributedDirector. To override default weights for a certain host, specify host-specific weights in the private DNS server configuration.

When the associated metric is referenced in the sorting decision, it will always be multiplied by the appropriate metric weight. In this way, you can specify that some metrics be weighted more than others. You may determine the weights that you want to use through experimentation. The weights given do not need to add up to 100.

The new availability metric allows the DistributedDirector to attempt to create a TCP connection to each distributed server on a configured port over a configurable time interval.

Examples

The following command configures default weights for the internal and external metrics:

ip director default weight drp-int 10 drp-ext 90

Related Commands

Command	Description
debug ip director parse	Shows debugging information for DistributedDirector parsing of TXT information.
debug ip director sort	Shows debugging information for DistributedDirector IP address sorting.
ip director access-list	Defines an access list for the DistributedDirector that specifies which subdomain names and host names should be sorted.
ip director cache	Enables the sorting cache on the DistributedDirector.
ip director default priorities	Sets default priorities for a specific metric on the DistributedDirector.
ip director drp rttprobe	Sets the protocol used by DRP agents for RTT probing in DistributedDirector.
ip director host priority	Configures the order in which the DistributedDirector considers metrics when selecting a server.
ip director host weights	Sets host-specific weights for the metrics that the DistributedDirector uses to determine the best server within a specific host name.
ip director server admin-pref	Configures a per-service administrative preference value.
ip director server portion	Sets the portion value for a specific server.
ip director server preference	Specifies DistributedDirector preference of one server over others or takes a server out of service.
show ip director default priority	Verifies the default configurations of DistributedDirector metrics.
show ip director default weights	Shows the DistributedDirector default weights.
show ip director servers	Displays the DistributedDirector server preference information.

ip director dfp

To configure the DistributedDirector Dynamic Feedback Protocol (DFP) agent with which the DistributedDirector should communicate, use the ip director dfp command in global configuration mode. To turn off the DFP agent, use the no form of this command.

ip director dfp ip-address [port] [retry n] [attempts n] [timeout n]

no ip director dfp ip-address [port] [retry n] [attempts n] [timeout n]

Syntax Description

ip-address	IP address.
port	(Optional) Port number to which the distributed servers are configured. The default value is 8080.
retry n	(Optional) Number of times a connection will be attempted. The default value is 5 attempts.
attempts n	(Optional) Delay, in seconds, between each attempt. The default value is 10,000 seconds.
timeout n	(Optional) Maximum amount of time, in seconds, for which DFP information is assumed valid. The default value is 10,000 seconds.

Syntax Description

The port default value is 8080.

The retry default value is 5 attempts.

The attempts default value is 10,000 seconds.

The timeout default value is 10,000 seconds.

Command Modes

Global configuration

Command History

Release	Modification
12.1(5)T	This command was introduced.

Usage Guidelines

A connection is attempted a specified number of times with a delay of a specified number of seconds between each attempt. Once a connection is established, the DFP protocol will run. If a time interval update has not occurred for this DFP session, the connection breaks and is reestablished as described above.

Examples

The following example configures the DistributedDirector to communicate with a specified DFP agent:

ip director dfp 10.0.0.1 retry 3 attempts 60 timeout 6000

ip director dfp security

To configure a security key for use when connecting to the Dynamic Feedback Protocol (DFP) client named, use the ip director dfp security command in global configuration mode. To turn off the security key, use the no form of this command.

ip director dfp security ip-address md5 string [timeout]

no ip director dfp security ip-address md5 string [timeout]

Syntax Description

ip-address	IP address for the service.
md5	Security data authentication. Message Digest 5.
string	Security key.
timeout	(Optional) Amount of time, in seconds, during which DistributedDirector will continue to accept a previously defined security key. The default value is 0 seconds.

Defaults

The timeout default value is 0 seconds.

Command Modes

Global configuration

Command History

Release	Modification
12.1(5)T	This command was introduced.

Usage Guidelines

The ip director dfp security command should be entered before configuring the ip director dfp command, resulting in a connection being made, but it can be entered independently of making a connection.

DFP allows servers to take themselves Out-of-Service and place themselves back In-Service. This function could result in a security risk because a network that is hacked could be shut down even though all the servers are still performing. An optional security vector is included in DFP to allow each message to be verified. The security vector is used to describe the security algorithm being used and to provide the data for that algorithm. The security vector itself is also extensible in that it specifies which security algorithm is being used. This specification allows different levels of security from MD5 to Data Encryption Standard (DES) to be used without overhauling the protocol and disrupting any installed base of equipment. If a receiving unit is configured for the specified security type, all DFP packets must contain that security vector or they are ignored. If a receiving unit is not configured for any security type, the security vector does not have to be present, and if it is present, it is ignored while the rest of the message is processed normally.

Examples

The following example configures the security key hello:

ip director dfp security 10.0.0.1 md5 hello 60

Related Commands

Command	Purpose
ip director dfp	Configures the DistributedDirector DFP agent with which the DistributedDirector should communicate.

ip director drp rttprobe

To set the protocol used by Director Response Protocol (DRP) agents for round-trip time (RTT) probing in DistributedDirector, use the ip director drp rttprobe command in global configuration mode. To disable the use of a protocol, use the no form of the command.

ip director drp rttprobe [tcp | icmp]

no ip director drp rttprobe [tcp | icmp]

Syntax Description

tcp	(Optional) Transmission Control Protocol.
icmp	(Optional) Internet Control Message Protocol.

Defaults

TCP

Command Modes

Global configuration

Command History

Release	Modification
12.2(4)T	This command was introduced.

Usage Guidelines

Both protocols can be activated, in which case DistributedDirector will instruct DRP agents to return the RTT collected from either the TCP or Internet Control Message Protocol (ICMP) protocol, whichever becomes available first. At any time, at least one of the protocols must be active.

To use only one protocol, enable the protocol you want to use, and then disable the protocol that was already configured.

Router(config)# ip director drp rttprobe icmp

Router(config)# no ip director drp rttprobe tcp

Examples

The following example shows that ICMP is configured for use by DRP agents for RTT probing:

Router(config)# ip director drp rttprobe icmp

Related Commands

Command	Description
ip director access-list	Defines an access list for the DistributedDirector that specifies which subdomain names and host names should be sorted.
ip director cache	Enables the sorting cache on the DistributedDirector.
ip director default priorities	Sets default priorities for a specific metric on the DistributedDirector.
ip director default weights	Configures default weight metrics for the DistributedDirector.
ip director host priority	Configures the order in which the DistributedDirector considers metrics when selecting a server.
ip director host weights	Sets host-specific weights for the metrics that the DistributedDirector uses to determine the best server within a specific host name.
ip director server admin-pref	Configures a per-service administrative preference value.
ip director server portion	Sets the portion value for a specific server.
ip director server preference	Specifies DistributedDirector preference of one server over others or takes a server out of service.
show ip director default priority	Verifies the default configurations of DistributedDirector metrics.
show ip director default weights	Shows the DistributedDirector default weights.
show ip director servers	Displays the DistributedDirector server preference information.

ip director drp synchronized

To activate clock synchronization between DistributedDirector and Director Response Protocol (DRP), use the ip director drp synchronized command in global configuration mode. To deactivate synchronization between the clocks in DistributedDirector and the DRPs, use the no form of this command.

ip director drp synchronized

no ip director drp synchronized

Syntax Description

This command has no arguments or keywords.

Defaults

Clock synchronization is deactivated.

Command Modes

Global configuration

Command History

Release	Modification
12.2(8)T	This command was introduced.

Usage Guidelines

This command is used in conjunction with boomerang racing.

When the ip dir drp synchronized command is configured, DistributedDirector specifies an absolute time at which the DRP agent should respond to the DNS client.

When no ip director drp synchronized is configured (which is the default), DistributedDirector specifies a relative time (based on the delay measured between DistributedDirector and the DRP agent) at which the DRP agent should respond to the DNS client.

Examples

In the following example, DistributedDirector and DRP clock synchronization are activated:

Router# ip director drp synchronized

Router# show running-config

ip host boom1 172.2.2.10 172.2.2.20 172.2.2.30 

ip director server 172.2.2.20 drp-association 172.4.4.2

ip director server 172.2.2.30 drp-association 172.4.4.3

ip director server 172.2.2.10 drp-association 172.4.4.1

ip director host boom1 

.

.

.

ip director drp synchronized

ip director host priority

To configure the order in which the DistributedDirector considers metrics when picking a server, use the ip director host priority command in global configuration mode. To turn off metric priorities, use the no form of this command.

ip director host host-name priority {[drp-int n] [drp-ext n] [drp-ser n] [drp-rtt n] [random n] [admin n] [portion n] [availability n] [route-map n]}

no ip director host host-name priority {[drp-int n] [drp-ext n] [drp-ser n] [drp-rtt n] [random n] [admin n] [portion n] [availability n] [route-map n]}

Syntax Description

host-name	Name of the host that maps to one or more IP addresses. Use the host-name argument to name the host that maps to one or more IP addresses. Do not use an IP address.
drp-int n	(Optional) Director Response Protocol (DRP) internal metric. The range is 1 to 100. This option sends a DRP request to all DRP server agents, asking them for the distance from themselves to the edge of their Border Gateway Protocol (BGP) autonomous system in the direction of the client originating the Domain Name System (DNS) query. This distance can be used along with the DRP external metric (drp-ext) to help determine the distance between the router and the client originating the DNS query. If the client and the DRP server agent are in the same autonomous system, this metric returns the Interior Gateway Protocol (IGP) cost metric between the client and the DRP server agent.
drp-ext n	(Optional) DRP external metric. The range is 1 to 100. This option sends a DRP request to all DRP server agents, asking them for the BGP distance between them and the client originating the DNS query. This distance represents the number of BGP hops between the autonomous system of the DRP server agent and the autonomous system of the client originating the DNS query. Because this is BGP information, the DRP server agents need to have access to full Internet BGP information in order for this metric to be useful.
drp-ser n	(Optional) DRP server metric. The range is 1 to 100. This option sends a DRP request to all DRP server agents, asking them for the IGP route metric between them and the distributed servers that they support. This distance can be used with the DRP internal metric (drp-int) to get a finer distance calculation between the distributed servers and the edge of the BGP autonomous system in the direction of the client originating the DistributedDirector query. If a true BGP border router is used as a DRP server agent, the DRP server metric will return the IGP route metric between the distributed server and the BGP border router (autonomous system edge). Because DRP server metrics should not change frequently, DistributedDirector issues DRP server queries (and caches the results) every 10 minutes.
drp-rtt n	(Optional) DRP round-trip time metric. The range is 1 to 100. This option sends a DRP request to all DRP server agents, asking them for the round-trip time between the DRP agent and the client originating the DNS query.
random n	(Optional) Random metric. The range is 1 to 100. This option selects a random number for each distributed server and defines the "best" server as the one with the smallest random number assignment. Using this metric alone results in random redirection of clients to the distributed servers. Because this metric requires no routing table information, it does not trigger DRP requests to the DRP server agents.
admin n	(Optional) Administrative metric. The range is 1 to 100. This option specifies a simple preference of one server over another. If the administrative metric has been explicitly set to zero, the Director will not consider the server, so the server is taken out of service.
portion n	(Optional) Portion metric. The range is 1 to 100. This option assigns a load "portion" to each server such that servers with a higher portion value will receive a larger percentage of connections at any one time.
availability n	(Optional) Availability metric. The range is 1 to 65,535. This option specifies the load information for the DistributedDirector. The default value is 65,535.
route-map n	(Optional) Route-map metric. The range is 1 to 100. This option specifies if a server should be offered to a client.

Defaults

The availability default value is 65,535.

Command Modes

Global configuration

Command History

Release	Modification
11.1(18)IA	This command was introduced.
12.1(5)T	This command was integrated into 12.1 T. The availability and route-map metrics were added.
12.2(8)T	The boomerang metric was added.

Usage Guidelines

Not all of the metrics need to be specified, but at least one must be specified. If the boomerang metric is specified at a given priority level, then all other metrics of lower priority (that is, having a higher priority number) for that host name are ignored. If the boomerang metric is being considered, then it is the final step in determining the best server.

The availability keyword allows the DistributedDirector to attempt to create a TCP connection to each distributed server on a configured port over a configurable time interval.

If multiple servers end up with the same metric value, the next metric is considered to determine the "best" server. If multiple metrics have the same priority value, the metrics are added to obtain a composite metric. For example, if two metrics have the same priority value, they are first multiplied by their weight values (if specified) and then added together to form the composite metric.

If you do not specify weights for a group of distributed servers, there are no default weights for the Director, and if you have specified priority values, the weight values are set to 1.

Any metrics that have a nonzero weight and that are assigned no priority value are set to a priority value of 101. They are considered after all other metrics that have priority values. As a result, if no priority values are specified for any metric, metrics are treated additively to form one composite metric.

If you do not use priority and multiple servers have the same metric value, the server whose last IP address was looked at will be returned as the "best" server. If you want to return a random IP address in the case of a tie, use metric priority with the random metric as the last criterion.

To turn off all priorities on all metrics associated with the defined host name, use the no ip director host priority command. You can turn off the priority for a specific metric or metrics using the no ip director host host-name priority [drp-int n] [drp-ext n] [drp-ser n] [drp-rtt n] [random n] [admin n] [portion n] [availability n] [route-map n] command.

Examples

The following example sets the external metric as the first priority and the administrative metric as the second priority:

Router(config)# ip director host www.xyz.com priority drp-ext 1 admin 2

The following example specifies the per-host priority of the metric, with a host named boom1, where the DRP internal metric is specified with a priority number of 1 and boomerang is specified with a priority number of 2:

Router(config)# ip director host BOOM1 priority drp-int 1 boomerang 2

Router(config)# do show running-config

ip host BOOM1 172.2.2.10 172.2.2.20 172.2.2.30 

.

.

.

ip director host BOOM1 

no ip director cache

ip dns primary boom1 soa boom1 boom1@com

ip director host boom1 priority drp-int 1 boomerang 2

Related Commands

Command	Description
ip director default priorities	Sets a default priority for a specific metric on DistributedDirector.
ip director default weights	Configures default weight metrics for DistributedDirector.
ip director host connect	Enables the DistributedDirector to verify that a server is available.
ip director host weights	Sets host-specific weights for the metrics that DistributedDirector uses to determine the best server within a specific host name.
show ip director default priority	Verifies the default configurations of DistributedDirector metrics.
show ip director default weights	Shows DistributedDirector default weights.
show ip director hosts	Displays DistributedDirector host information.

ip director host weights

To set host-specific weights for the metrics that the DistributedDirector uses to determine the best server within a specific host name, use the ip director host weights command in global configuration mode. To turn off weights for a host, use the no form of this command.

ip director host host-name weights {[drp-int n] [drp-ext n] [drp-ser n] [drp-rtt n] [random n] [admin n] [portion n] [availability n] [route-map n]}

no ip director host host-name weights {[drp-int n] [drp-ext n] [drp-ser n] [drp-rtt n] [random n] [admin n] [portion n] [availability n] [route-map n]}

Syntax Description

host-name	Name of the host that maps to one or more IP addresses. Do not use an IP address.
drp-int n	(Optional) Director Response Protocol (DRP) internal metric. The range is 1 to 100. This option sends a DRP request to all DRP server agents, asking them for the distance from themselves to the edge of their Border Gateway Protocol (BGP) autonomous system in the direction of the client originating the Domain Name System (DNS) query. This distance can be used along with the DRP external metric (drp-ext) to help determine the distance between the router and the client originating the DNS query. If the client and the DRP server agent are in the same autonomous system, this metric returns the Interior Gateway Protocol (IGP) cost metric between the client and the DRP server agent.
drp-ext n	(Optional) DRP external metric. The range is 1 to 100. This option sends a DRP request to all DRP server agents, asking them for the BGP distance between them and the client originating the DNS query. This distance represents the number of BGP hops between the autonomous system of the DRP server agent and the autonomous system of the client originating the DNS query. Because this is BGP information, the DRP server agents need to have access to full Internet BGP information in order for this metric to be useful.
drp-ser n	(Optional) DRP server metric. The range is 1 to 100. This option sends a DRP request to all DRP server agents, asking them for the IGP route metric between them and the distributed servers that they support. This distance can be used with the DRP internal metric (drp-int) to get a finer distance calculation between the distributed servers and the edge of the BGP autonomous system in the direction of the client originating the DistributedDirector query. If a true BGP border router is used as a DRP server agent, the DRP server metric will return the IGP route metric between the distributed server and the BGP border router (autonomous system edge). Because DRP server metrics should not change frequently, DistributedDirector issues DRP server queries (and caches the results) every 10 minutes.
drp-rtt n	(Optional) DRP round-trip time metric. The range is 1 to 100. This option sends a DRP request to all DRP server agents, asking them for the round-trip time between the DRP agent and the client originating the DNS query.
random n	(Optional) Random metric. The range is 1 to 100. This option selects a random number for each distributed server and defines the "best" server as the one with the smallest random number assignment. Using this metric alone results in random redirection of clients to the distributed servers. Because this metric requires no routing table information, it does not trigger DRP requests to the DRP server agents.
admin n	(Optional) Administrative metric. The range is 1 to 100. This option specifies a simple preference of one server over another. If the administrative metric has been explicitly set to zero, the Director will not consider the server, so the server is taken out of service.
portion n	(Optional) Portion metric. The range is 1 to 100. This option assigns a load "portion" to each server such that servers with a higher portion value will receive a larger percentage of connections at any one time.
availability n	(Optional) Availability metric. The range is 1 to 65,535. This option specifies the load information for the DistributedDirector. The default value is 65,535.
route-map n	(Optional) Route-map metric. The range is 1 to 100. This option specifies if a server should be offered to a client.

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Note No host weights are set. If the ip director default-weights command is configured, the configured weights are the default.

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Defaults

The availability default value is 65,535.

Command Modes

Global configuration

Command History

Release	Modification
11.1(25)IA	This command was introduced.
12.0(3)T	This command was integrated into Cisco IOS Release 12.0(3)T.
12.1(5)T	The availability and route-ma