ip director server availability through ttl ip ip director server availability through ttl ip

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2 ip director server availability ip director server availability Note Effective with Cisco IOS 12.4(24)T, the ipdirectorserveravailabilitycommand is not available in Cisco IOS software. To configure a default availability value for all ports on a server, use theipdirectorserveravailabilitycommand in global configuration mode. To restore the default, use the no form of this command. ip director server ip-address availability {availability-value dfp [ availability-value ]} no ip director server ip-address availability {availability-value dfp [ availability-value ]} Syntax Description ip-address availability value dfp IP address of the IP director server. Integer in the range from 0 to that specifies the availability value as it would be represented on the DistributedDirector system. (Optional) When used with the dfp keyword, the availability value is for the LocalDirector system. Specifies that Dynamic Feedback Protocol is configured. Command Default The availability default value is Command Modes Global configuration Command History 12.1(5)T 12.2(33)SRA 12.2SX This command was introduced. This command was integrated into Cisco IOS 12.2(33)SRA. This command is supported in the Cisco IOS 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. 2

3 ip director server availability 12.4(24)T This command was removed. Usage Guidelines There are two methods for specifying a default availability value. These two methods exist because the LocalDirector and the DistributedDirector deal with values in two different ways. All metrics for the DistributedDirector are arranged such that lower is better; however the LocalDirector load information is calculated such that higher is better. Thus, the DistributedDirector translates the metric value upon receipt from the LocalDirector by subtracting the availability from the maximum possible value of Command Examples To configure a default availability to be used if there is no other valid availability information, the following configuration would suffice. The following example shows how to specify the LocalDirector load and DistributedDirector availability, respectively: Router(config)# ip director server availability dfp 1 Router(config)# ip director server availability To make the availability clear and to allow for specifying numbers in both schemes easily, there are two methods of specifying availability information. If the servers are running multiple serves, it may be necessary to configure the default availability value on a per-port basis by using theipdirectorserverportavailability command. Router(config)# ip director server port availability dfp Router(config)# ip director server port availability dfp Related Commands Command ip director server port availability Description Configures a default availability value for a specific port on a server. 3

4 ip director server port availability ip director server port availability Note Effective with Cisco IOS 12.4(24)T, the ipdirectorserverportavailabilitycommand is not available in Cisco IOS software. To configure a default availability value for a specific port on a server, use theipdirectorserverportavailabilitycommand in global configuration mode. To restore the default, use the no form of this command. ip director server ip-address port availability {availability-value dfp [ availability-value ]} no ip director server ip-address port availability {availability-value dfp [ availability-value ]} Syntax Description ip-address availability value dfp IP address of the IP director server. Integer in the range from 0 to that specifies the availability value as it would be represented on the DistributedDirector system. (Optional) When used with the dfp keyword, the availability value is for the LocalDirector system. Specifies that Dynamic Feedback Protocol is configured. Command Default The availability default value is Command Modes Global configuration Command History 12.1(5)T 12.2(33)SRA 12.2SX This command was introduced. This command was integrated into Cisco IOS 12.2(33)SRA. This command is supported in the Cisco IOS 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. 4

5 ip director server port availability 12.4(24)T This command was removed. Usage Guidelines Two methods are available for specifying a default availability value because the LocalDirector and the DistributedDirector process these values differently. All metrics for the DistributedDirector are arranged such that a lower value is better. The LocalDirector load information is calculated such that a higher value is better. As a result, the DistributedDirector translates the metric value upon receipt from the LocalDirector by subtracting the availability from the maximum possible value of availability value. Command Examples The following examples show how to make the availability clear and how to specify numbers in both methods. If the servers are running multiple serves, it may be necessary to configure the default availability value on a per-port basis by using theipdirectorserverportavailability command. Router(config)# ip director server port availability dfp Router(config)# ip director server port availability dfp The following example shows how to configure the LocalDirector load and DistributedDirector availability, respectively, when there is no other valid availability information. Router(config)# ip director server availability dfp 1 Router(config)# ip director server availability Related Commands Command ip director server availability Description Configures a default availability value for all ports on a server. 5

6 ip director server reinstatement ip director server reinstatement Note Effective with Cisco IOS 12.4(24)T, the ipdirectorserverreinstatementcommand is not available in Cisco IOS software. To configure a DistributedDirector to automatically detect when a server is running and mark it as available, use the ipdirectorserverreinstatement command in global configuration mode. To restore the default, use the no form of this command. ip director server ip-address reinstatement no ip director server ip-address reinstatement Syntax Description ip-address IP address of the server. Command Default Automatic server reinstatement is enabled. Command Modes Global configuration Command History 12.1(5)T 12.2(33)SRA 12.2SX 12.4(24)T This command was introduced. This command was integrated into Cisco IOS 12.2(33)SRA. This command is supported in the Cisco IOS 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. This command was removed. Usage Guidelines If a DistributedDirector detects that a server is unavailable and the DistributedDirector has enabled that server to be restored to its previous effective state, the ipdirectorserverreinstatement command must be issued to bring the server up again. When a DistributedDirector detects that a server is unavailable, it stops attempting to create a TCP connection to that server. The exception is when the DistributedDirector was configured by a user to continue connection attempts. 6

7 ip director server reinstatement Command Examples The following example shows how to configure a DistributedDirector to automatically detect if server is running. If server is not running, traffic is redirected to server Router(config)# ip director server reinstatement Router(config)# ip director server reinstatement 7

8 ip director server route-map ip director server route-map Note Effective with Cisco IOS 12.4(24)T, the ipdirectorserverroute-mapcommand is not available in Cisco IOS software. To configure a DistributedDirector to use the source autonomous systems identifier as a server-selection criterion, use the ipdirectorserverroute-map command in global configuration mode. To restore the default, use the no form of this command. ip director server ip-address route-map map-name no ip director server ip-address route-map map-name Syntax Description ip-address map-name IP address of the server. Name of the route map. Command Default Use of the autonomous systems identifier as a selection criterion is disabled. Command Modes Global configuration Command History 12.1(5)T 12.2(33)SRA 12.2SX 12.4(24)T This command was introduced. This command was integrated into Cisco IOS 12.2(33)SRA. This command is supported in the Cisco IOS 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. This command was removed. Usage Guidelines Each autonomous system that makes up the Internet has a numeric identifier that routing protocols use. The ipdirectorserverroute-mapcommand provides a way for a DistributedDirector to use the source autonomous system (the autonomous system in which the client resides) identifier as a server-selection criterion. 8

9 ip director server route-map The route-map mechanism is normally used in Cisco IOS software to map or associate routes from one routing protocol to another. For example, a route learned via Open Shortest Path First (OSPF) could be passed or mapped to Routing Information Protocol (RIP). The ipdirectorserverroute-mapcommand uses the existing route-map infrastructure to access routing data. For the route-map mechanism to run correctly, theiphost, ipdnsprimary, andipdirectorhost commands must be configured before issuing the ipdirectorserverroute-map command. Command Examples The following example shows how to configure a DistributedDirector to have all clients using autonomous system 200 use server and all other clients use server : Router(config)# ip host Router(config)# ip dns primary soa ns.xyz.com blank.com Router(config)# ip director host priority route-map 1 Router(config)# ip director server route-map block200 Router(config)# ip director server route-map allow200 Router(config)# ip as-path access-list 100 permit 200 Router(config)# ip as-path access-list 101 deny 200 Router(config)# route-map allow 200 permit 1 Router(config)# match as-path 100 Router(config)# route-map block200 permit 1 Router(config)# match as-path 101 Related Commands Command ip director host ip dns primary ip host Description Defines the virtual hostname to be used for the distributed servers. Identifies the DistributedDirector as the primary DNS name server for a domain and as the statement-of-authority record source. Defines a static hostname-to-address mapping in the host cache. 9

10 ip director server verify-url ip director server verify-url Note Effective with Cisco IOS 12.4(24)T, the ipdirectorserververify-urlcommand is not available in Cisco IOS software. To configure a DistributedDirector to search for a URL string with a specified server and at a specific time interval, use theipdirectorserververify-urlcommand in global configuration mode. To turn off this URL search, use the no form of this command. ip director server ip-address port verify-url string connection-interval seconds no ip director server ip-address port verify-url string connection-interval seconds Syntax Description ip-address port string connection-interval seconds IP address of the server. Port number to be associated with the host. Full URL or pathname. Specifies a time between availability checks. Time, in seconds, between availability checks. Command Default No URL search is specified. Command Modes Global configuration Command History 12.1(5)T 12.2(33)SRA 12.2SX 12.4(24)T This command was introduced. This command was integrated into Cisco IOS 12.2(33)SRA. This command is supported in the Cisco IOS 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. This command was removed. 10

11 ip director server verify-url Usage Guidelines If a URL is found and an HTTP reply code is received, the DistributedDirector marks all servers associated with the hostname as being up. If an error code is received, the DistributedDirector marks all servers associated with the hostname as being down. Servers that are in a down state cannot be selected. If verification URLs have been configured for both a hostname and a specific server, the status returned from the connection on behalf of the specific server overrides the configuration because the status is considered more specific than a single hostname. The same URL may be specified for verifying multiple pairs, in which case the smallest configured availability checks are used for all pairs and one connection is made to verify all pairs. Command Examples The following example shows how to configure a DistributedDirector to search the server with IP address , port 80, for the URL string every 120 seconds: Router(config)# ip director server verify-url connection-interval

12 ip director server weights ip director server weights Note Effective with Cisco IOS 12.4(24)T, the ipdirectorserverweightscommand is not available in Cisco IOS software. To configure a per-service per-metric weight, use theipdirectorserverweights command in global configuration mode. To turn off a metric weight configuration, use the no form of this command. ip director server ip-address port weights metric-name metric-weight no ip director server ip-address port weights metric-name metric-weight Syntax Description ip-address port metric-name metric-weight IP address of the server. Port number to be associated with the host. Name of the metric used. Weight of the metric used. Command Default No per-service-per-metric weight is configured. Command Modes Global configuration Command History 12.1(5)T 12.2(33)SRA 12.2SX 12.4(24)T This command was introduced. This command was integrated into Cisco IOS 12.2(33)SRA. This command is supported in the Cisco IOS 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. This command was removed. 12

13 ip director server weights Usage Guidelines When the metric name is referenced with respect to this server and port, the value of the metric is multiplied by the metric weight. Command Examples The following example shows how to configure a DistributedDirector to check port 80 for an availability metric of 3. Router(config)# ip director server weights availability 3 13

14 ip drp access-group ip drp access-group To control the sources of Director Response Protocol (DRP) queries to the DRP server agent, use the ipdrpaccess-group command in global configuration mode. To remove the access list, use the no form of this command. ip drp access-group access-list-number no ip drp access-group access-list-number Syntax Description access-list-number Number of a standard IP access list in the range from 1 to 99 or from 1300 to Command Default The DRP server agent will answer all queries. Command Modes Global configuration Command History 11.2 F This command was introduced. 12.2(33)SRA 12.2SX This command was integrated into Cisco IOS 12.2(33)SRA. This command is supported in the Cisco IOS 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. Usage Guidelines This command applies an access list to the interface, thereby controlling which devices can send queries to the DRP Server Agent. If both an authentication key chain and an access group have been specified, both security measures must permit access before a request is processed. Command Examples The following example configures access list 1, which permits only queries from the host at : Router(config)# access-list 1 permit Router(config)# ip drp access-group 1 14

15 ip drp access-group Related Commands Command ip drp authentication key-chain show ip drp Description Configures authentication on the DRP Server Agent for DistributedDirector. Displays information about the DRP Server Agent for DistributedDirector. 15

16 ip drp authentication key-chain ip drp authentication key-chain To configure authentication on the Director Response Protocol (DRP) Server Agent for DistributedDirector, use the ipdrpauthenticationkey-chain command in global configuration mode. To remove the key chain, use the no form of this command. ip drp authentication key-chain name-of-chain no ip drp authentication key-chain name-of-chain Syntax Description name-of-chain Name of the key chain containing one or more authentication keys. Command Default No authentication is configured for the DRP Server Agent. Command Modes Global configuration Command History 11.2 F This command was introduced. 12.2(33)SRA 12.2SX This command was integrated into Cisco IOS 12.2(33)SRA. This command is supported in the Cisco IOS 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. Usage Guidelines When a key chain and key are configured, the key is used to authenticate all DRP requests and responses. The active key on the DRP Server Agent must match the active key on the primary agent. Use the key and key-string commands to configure the key. Command Examples The following example configures a key chain named ddchain : Router(config)# ip drp authentication key-chain ddchain 16

17 ip drp authentication key-chain Related Commands Command accept-lifetime ip drp access-group key key chain key-string (authentication) send-lifetime show ip drp show key chain Description Sets the time period during which the authentication key on a key chain is received as valid. Controls the sources of DRP queries to the DRP Server Agent. Identifies an authentication key on a key chain. Enables authentication for routing protocols. Specifies the authentication string for a key. Sets the time period during which an authentication key on a key chain is valid to be sent. Displays information about the DRP Server Agent for DistributedDirector. Displays authentication key information. 17

18 ip drp domain ip drp domain To add a new domain to the DistributedDirector client or to configure an existing domain, use the ipdrpdomaincommand 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 drp domain domain-name no ip drp domain domain-name Syntax Description domain-name The specified domain name. Command Default No default domain is configured. Command Modes Global configuration Command History 12.2(8)T 12.2(33)SRA 12.2SX This command was introduced. This command was integrated into Cisco IOS 12.2(33)SRA. This command is supported in the Cisco IOS 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. Usage Guidelines The ipdrpdomain command can be used only on a Director Response Protocol (DRP) agent. The boomerang client is the DRP agent. Enabling this command puts the client in boomerang configuration mode. Use the ipdrpdomain command to enter a new or existing domain name. Entering a new domain name creates a new domain, and entering an existing domain name allows the user to configure the specified domain. When a domain name is configured on the boomerang client, the user can configure specific parameters, such as server address, aliases, and time to live (TTL) values, for that domain. When a Director Response Protocol (DRP) agent receives a Domain Name System (DNS) racing message from boomerang servers such as DistributedDirector, the DRP agent extracts the specified domain name (for example, in the DNS message. 18

19 ip drp domain Command Examples In the following example, a domain named is added on the boomerang client: Router(config)# ip drp domain Router# show running-config... ip drp domain Related Commands Command alias (boomerang) server (boomerang) show ip drp show ip drp boomerang ttl dns ttl ip Description Configures an alias name for a specified domain. Configures the server address for a specified boomerang domain. Displays DRP statistics on DistributedDirector or a DRP server agent. Displays boomerang information on the DRP agent. Configures the number of seconds for which an answer received from the boomerang client will be cached by the DNS client. Configures the IP TTL value for the boomerang response packets sent from the boomerang client to the DNS client in number of hops. 19

20 ip drp server ip drp server To enable the Director Response Protocol ( DRP) Server Agent that works with DistributedDirector, use the ipdrpservercommand inglobal configuration mode. To disable the DRP Server Agent, use the no form of this command. ip drp server no ip drp server Syntax Description This command has no arguments or keywords. Command Default Disabled Command Modes Global configuration Command History 11.2 F This command was introduced. 12.2(33)SRA 12.2SX This command was integrated into Cisco IOS 12.2(33)SRA. This command is supported in the Cisco IOS 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. Command Examples The following example enables the DRP Server Agent: Router(config)# ip drp server Related Commands Command ip drp access-group ip drp authentication key-chain Description Controls the sources of DRP queries to the DRP Server Agent. Configures authentication on the DRP Server Agent for DistributedDirector. 20

21 ip drp server Command show ip drp Description Displays information about the DRP Server Agent for DistributedDirector. 21

22 ip host ns ip host ns To create a name server (NS) resource record to be returned when a Domain Name System (DNS) server is queried for the associated domain, use theiphostns command in global configuration mode. To remove the NS records, use the no form of this command. ip host domain-name ns server-name no ip host domain-name ns server-name Syntax Description domain-name server-name Name of the authority that is delegated to another NS, such as a second-level DistributedDirector. Name of the second-level DNS server. Command Default None. Command Modes Global configuration Command History 12.2(2)T This command was introduced. Usage Guidelines The iphostns command allows a DistributedDirector to distribute the server selection process to multiple DistributedDirectors, providing greater scalability and better administrative control. A DNS server can delegate responsibility for a domain to another DNS server by returning an NS record when queried. This task is especially useful to a DistributedDirector because determining the best DNS reply may be time consuming. To expedite replies, a DistributedDirector can return an NS record, delegating authority for the requested data to one or more second-level DistributedDirectors. Command Examples The following example shows a top-level DistributedDirector that uses the low-cost metric random to distribute its load over second-level DistributedDirectors: Examples Router(config)# ip host ns ns.xyz.com Router(config)# ip host ns2.xyz.com Router(config)# ip director host ns.xyz.com priority random 1 Router(config)# ip dns primary soa ns2.xyz.com 22

23 ip host ns The following example shows second-level DistributedDirectors that use more expensive metrics such as drp-ext and drp-rtt to perform precise server selection. Examples Router(config)# ip host Router(config)# ip director host priority drp-ext 1 Router(config)# ip director host priority drp-rtt 2 Router(config)# ip director server drp-association Router(config)# ip director server drp-association Router(config)# ip director server drp-association

24 server (boomerang) server (boomerang) To configure the server address for a specified boomerang domain, use the servercommand 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. server server-ip-address no server server-ip-address Syntax Description server-ip-address IP address of the specified server. Command Default No default behavior or values. Command Modes Boomerang configuration Command History 12.2(8)T This command was introduced. Usage Guidelines The servercommand can be used only on a Director Response Protocol (DRP) agent. The boomerang client is the Director Response Protocol (DRP) agent. Use the server command to specify a server address that is to be associated with a given domain name. This configuration overrides the server-to-drp agent association that is configured on DistributedDirector. Command Examples The following example configures the server for a domain named The server address for is : Router(config)# ip drp domain Router(config-boomerang)# server Router# show running-config... ip drp domain content-server

25 server (boomerang) Related Commands Command alias (boomerang) ip drp domain show ip drp show ip drp boomerang ttl dns ttl ip Description Configures an alias name for a specified domain. Adds a new domain to the DistributedDirector client or configures an existing domain and puts the client in boomerang configuration mode. Displays DRP statistics on DistributedDirector or a DRP server agent. Displays boomerang information on the DRP agent. Configures the number of seconds for which an answer received from the boomerang client will be cached by the DNS client. Configures the IP TTL value for the boomerang response packets sent from the boomerang client to the DNS client in number of hops. 25

26 show ip director default show ip director default Note Effective with Cisco IOS 12.4(24)T, the showipdirectordefaultcommand is not available in Cisco IOS software. To verify default metric configuration information for DistributedDirector metrics, use the showipdirectordefaultcommand in privileged EXEC mode. show ip director default [priority weight] Syntax Description priority weight (Optional) Default priorities for metrics. (Optional) Displays the weights for metrics. Command Modes Privileged EXEC Command History 12.2(4)T 12.4(24)T This command was introduced. This command was removed. Usage Guidelines Use this command to verify default metric configurations. Command Examples The following is sample output from the showipdirectordefaultprioritycommand: Router# show ip director default priority Director default metric priorities: random priority = 2 DRP route lookup external to AS priority = 1 administrative preference priority = 0 DRP route lookup internal to AS priority = 0 DRP distance to associated server priority = 0 portion priority = 0 Round-trip time from DRP to client priority = 0 DFP originated weight priority = 0 Route-map evaluation priority = 0 26

27 show ip director default Related Commands Command ip director default priorities Description Sets default priorities for DistributedDirector metrics. 27

28 show ip director dfp show ip director dfp Note Effective with Cisco IOS 12.4(24)T, the showipdirectordfpcommand is not available in Cisco IOS software. To display information about the current status of the DistributedDirector connections with a particular Dynamic Feedback Protocol (DFP) agent, use theshowipdirectordfp command in EXEC mode. show ip director dfp [host-name ip-address] Syntax Description host-name ip-address (Optional) Host name. (Optional) IP address. Command Modes EXEC Command History 12.1(5)T 12.2(33)SRA 12.2SX 12.4(24)T This command was introduced. This command was integrated into Cisco IOS 12.2(33)SRA. This command is supported in the Cisco IOS 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. This command was removed. Command Examples The following is sample output from the showipdirectordfp command: Router# show ip director dfp : Max retries: 5 Timeout between connect attempts: 60 Timeout between updates: 90 Last update received: 00:00:12 ago Server Port BindID Address Mask Max retries: 5 Timeout between connect attempts: 60 Timeout between updates: 90 28

29 show ip director dfp Last update received: 00:00:44 ago Server Port BindID Address Mask

30 show ip director drp show ip director drp Note Effective with Cisco IOS 12.4(24)T, the showipdirectordrpcommand is not available in Cisco IOS software. To display information that the DistributedDirector has about specific Director Response Protocol (DRP) agents, use theshowipdirectordrpcommand in privileged EXEC mode. show ip director drp [host-name ip-address] Syntax Description host-name ip-address (Optional) DRP hostname. (Optional) DRP IP address. Command Modes Privileged EXEC Command History 12.1(5)T 12.2(33)SRA 12.4(24)T This command was introduced. This command was integrated into Cisco IOS 12.2(33)SRA. This command was removed. Usage Guidelines The showipdirectordrpcommand displays host-specific statistics, such as the number of queries received and the number of replies sent for a host. Command Examples The following is sample output from theshowipdirectordrpcommand: Router# show ip director drp DRP agent : 14 requests, 6 replies, 4 requeries, 0 bad replies Supported Servers: DRP agent : 14 requests, 6 replies, 4 requeries, 0 bad replies Supported servers:

31 show ip drp show ip drp To display information about the Director Response Protocol (DRP) Server Agent for DistributedDirector, use the showipdrpcommand inuser EXEC or privileged EXEC mode. show ip drp Syntax Description This command has no arguments or keywords. Command Modes User EXEC Privileged EXEC Command History 11.2 F This command was introduced. 12.2(33)SRA 12.2SX This command was integrated into Cisco IOS 12.2(33)SRA. This command is supported in the Cisco IOS 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. Command Examples The following is sample output from the showipdrp command: Router# show ip drp Director Responder Protocol Agent is enabled 717 director requests, 712 successful lookups, 5 failures, 0 no route Authentication is enabled, using test key-chain The table below describes the significant fields shown in the display. Table 1: show ip drp Field Descriptions Field director requests successful lookups Description Number of DRP requests that have been received (including any using authentication key-chain encryption that failed). Number of successful DRP lookups that produced responses. 31

32 show ip drp Field failures Description Number of DRP failures (for various reasons including authentication key-chain encryption failures). Related Commands Command ip drp access-group ip drp authentication key-chain Description Controls the sources of DRP queries to the DRP server agent. Configures authentication on the DRP server agent for DistributedDirector. 32

33 show ip drp boomerang show ip drp boomerang To display the status of various boomerang domains, use the showipdrpboomerang command in privileged EXEC mode. show ip drp boomerang [ domain-name ] Syntax Description domain-name (Optional) Specified domain name. Command Modes Privileged EXEC Command History 12.2(8)T This command was introduced. Usage Guidelines The showipdrpboomerang command can be used on the boomerang client to display the status of the various boomerang domains. The following information can be shown for each domain: Alias information--the number of DNS requests for each alias. Content server address information: Number of DNS requests. Number of requests dropped because server is down. Number of requests dropped because there is no original server. Number of requests dropped because of security failures. Command Examples The following is sample output from the showipdrpboomerang command: Router# show ip drp boomerang DNS packets with unknown domain 0 Domain Content server up Origin server DNS A record requests 0 Dropped (server down) 0 Dropped (no origen server) 0 Security failures 0 Alias DNS A record requests 0 33

34 show ip drp boomerang Related Commands Command alias (boomerang configuration) ip drp domain server (boomerang configuration) show ip drp ttl dns ttl ip Description Configures an alias name for a specified domain. Adds a new domain to the DistributedDirector client or configures an existing domain and puts the client in boomerang configuration mode. Configures the server address for a specified boomerang domain. Displays DRP statistics on DistributedDirector or a DRP server agent. Configures the number of seconds for which an answer received from the boomerang client will be cached by the DNS client. Configures the IP TTL value for the boomerang response packets sent from the boomerang client to the DNS client in number of hops. 34

35 ttl dns ttl dns To configure the number of seconds for which an answer received from the boomerang client will be cached by the Domain Name System (DNS) client, use the ttldnscommand 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. ttl dns seconds no ttl dns seconds Syntax Description seconds Integer in the range from 10 to that specifies the number of seconds for which an answer received from the boomerang client will be cached by the DNS client. Command Default No default behavior or values. Command Modes Boomerang configuration Command History 12.2(8)T This command was introduced. Usage Guidelines The ttldnscommand can be used only on a Director Response Protocol (DRP) agent. The boomerang client is the DRP agent. The ttldnscommand configures the number of seconds for which the DNS client can cache a boomerang reply from a boomerang client. Command Examples In the following example, the number of seconds for which the DNS client can cache a boomerang reply from a boomerang client is configured as 10: Router(config)# ip drp domain Router(config-boomerang)# ttl dns 10 Router# show running-config... ip drp domain dns-ttl 10 35

36 ttl dns Related Commands Command alias (boomerang configuration) ip drp domain server (boomerang configuration) show ip drp show ip drp boomerang ttl ip Description Configures an alias name for a specified domain. Adds a new domain to the DistributedDirector client or configures an existing domain and puts the client in boomerang configuration mode. Configures the server address for a specified boomerang domain. Displays DRP statistics on DistributedDirector or a DRP server agent. Displays boomerang information on the DRP agent. Configures the IP TTL value for the boomerang response packets sent from the boomerang client to the DNS client in number of hops. 36

37 ttl ip ttl ip To configure the IP time-to-live (TTL) value for the boomerang response packets sent from the boomerang client to the DNS client, use the ttlipcommand 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. ttl ip hops no ttl ip hops Syntax Description hops Integer in the range from 1 to 255 that specifies the number of hops that occur between the boomerang client and the DNS client before the boomerang response packet fails. Command Default No default behavior or values. Command Modes Boomerang configuration Command History 12.2(8)T This command was introduced. Usage Guidelines The ttlipcommand can be used only on a Director Response Protocol (DRP) agent. The boomerang client is the DRP agent. The ttlip command configures the maximum number of hops allowed between the boomerang client and the DNS client, after which the boomerang response packet fails. If the user wants to restrict the contending proxies only to nearby ones, the value of the ttlip command can be set to a specific number within the allowed range. Any proxy outside of this range will be automatically disqualified in the boomerang race because its replies will never reach the DNS client. Because the ttlipcommand specifies the number of hops for which a response from a client will live, it allows faraway proxies to avoid wasting bandwidth. Command Examples In the following example, the number of hops that occur between the boomerang client and the DNS client before the boomerang response packet fails is configured as 2: Router(config)# ip drp domain Router(config-boomerang)# ttl ip 2 Router# show running-config 37

38 ttl ip... ip drp domain ip-ttl 2 Related Commands Command alias (boomerang) ip drp domain server (boomerang ) show ip drp show ip drp boomerang ttl dns Description Configures an alias name for a specified domain. Adds a new domain to the DistributedDirector client or configures an existing domain and puts the client in boomerang configuration mode. Configures the server address for a specified boomerang domain. Displays DRP statistics on DistributedDirector or a DRP server agent. Displays boomerang information on the DRP agent. Configures the number of seconds for which an answer received from the boomerang client will be cached by the DNS client. 38