Table Of Contents

ignore lsa mospf

import ipv4

inherit peer-policy

inherit peer-session

input-queue

ip as-path access-list

ip authentication key-chain eigrp

ip authentication mode eigrp

ip bandwidth-percent eigrp

ip bgp fast-external-fallover

ip bgp-community new-format

ip community-list

ip default-network

ip dvmrp metric

ip extcommunity-list

ip fast-convergence

ip hello-interval eigrp

ip hold-time eigrp

ip local policy route-map

ip multicast cache-headers

ip next-hop-self eigrp

ip ospf area

ip ospf authentication

ip ospf authentication-key

ip ospf cost

ip ospf database-filter all out

ip ospf dead-interval

ip ospf demand-circuit

ip ospf flood-reduction

ip ospf hello-interval

ip ospf lls

ip ospf message-digest-key

ip ospf mtu-ignore

ip ospf name-lookup

ip ospf network

ip ospf priority

ip ospf resync-timeout

ip ospf retransmit-interval

ip ospf transmit-delay

ignore lsa mospf

To suppress the sending of syslog messages when the router receives link-state advertisement (LSA) Type 6 Multicast OSPF (MOSPF) packets, which are unsupported, use the ignore lsa mospf command in router configuration mode. To restore the sending of syslog messages, use the no form of this command.

ignore lsa mospf

no ignore lsa mospf

Syntax Description

This command has no arguments or keywords.

Defaults

This command is disabled by default. Each MOSPF packet causes the router to send a syslog message.

Command Modes

Router configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

Cisco routers do not support LSA Type 6 MOSPF packets, and they generate syslog messages if they receive such packets. If the router is receiving many MOSPF packets, you might want to configure the router to ignore the packets and thus prevent a large number of syslog messages.

Examples

The following example configures the router to suppress the sending of syslog messages when it receives MOSPF packets:

router ospf 109

 ignore lsa mospf

import ipv4

To configure an import map to import IPv4 prefixes from the global routing table to a VRF table, use the import ipv4 command in VRF configuration submode. To remove the import map, use the no form of this command.

import ipv4 unicast | multicast [prefix-limit] route-map

no import ipv4 unicast | multicast [prefix-limit] route-map

Syntax Description

unicast	Specifies IPv4 unicast prefixes to import.
multicast	Specifies IPv4 multicast prefixes to import.
prefix-limit	(Optional) Specifies the number of prefixes to import. The range for this argument is a number from 1 to 2147483647.
route-map	Specifies the route map to be used as an import route map for the VRF.

Defaults

No default behavior or values

Command Modes

VRF configuration submode

Command History

Release	Modification
12.0(29)S	This command was introduced.
12.2(25)S	This command was integrated into Cisco IOS Release 12.2(25)S.
12.3(14)T	This command was integrated into Cisco IOS Release 12.3(14)T.

Usage Guidelines

IP prefixes that are defined for import are processed through a match clause in a route map. The prefixes that pass through the route map are imported into the VRF. A maximum of 5 VRFs per router can be configured to import IPv4 prefixes from the global routing table. 1000 prefixes per VRF are imported by default. You can manually configure from 1 to 2147483647 prefixes for each VRF. We recommend that you use caution if you manually configure the prefix import limit. Configuring the router to import too many prefixes can interrupt normal router operation. Only IPv4 unicast and multicast prefixes can be imported to a VRF with this feature. IPv4 prefixes imported into a VRF using this feature cannot be imported into a VPNv4 VRF.

No MPLS or Route Target Configuration is Required

No MPLS or route target (import/export) configuration is required.

Import Behavior

Import actions are triggered when a new routing update is received or when routes are withdrawn. During the initial BGP update period, the import action is postponed to allow BGP to convergence more quickly. Once BGP converges, incremental BGP updates are evaluated immediately and qualified prefixes are imported as they are received.

Examples

The following example, beginning in global configuration mode, imports all unicast prefixes from the 10.24.240.0/22 subnet into the VRF named GREEN. An IP prefix list is used to define the imported IPv4 prefixes. The route map is attached to the Ethernet 0 interface. Unicast RPF verification for VRF GREEN is enabled.

ip prefix-list COLORADO permit 10.24.240.0/22 

!

ip vrf GREEN

 rd 100:10

 import ipv4 unicast 1000 map UNICAST

 exit

route-map UNICAST permit 10

 match ip address prefix-list COLORADO

 exit

interface Ethernet 0

 ip policy route-map UNICAST 

 ip verify unicast vrf GREEN permit 

end

Related Commands

Command	Description
ip verify unicast vrf	Enables Unicast Reverse Path Forwarding verification for the specified VRF.
ip vrf	Configures a VRF routing table.
rd	Creates routing and forwarding tables for a VRF.
show ip bgp	Displays entries in the BGP routing table.
show ip bgp vpnv4	Displays VPN address information from the BGP table.
show ip vrf	Displays the set of defined VRFs and associated interfaces.

inherit peer-policy

To configure a peer policy template to inherit the configuration from another peer policy template, use the inherit peer-policy command in policy-template configuration mode. To remove an inherit statement from a peer policy template, use the no form of this command.

inherit peer-policy policy-template sequence-number

no inherit peer-policy policy-template sequence-number

Syntax Description

peer-policy	Name of the peer policy template to be inherited.
sequence-number	Sequence number that sets the order in which the peer policy template is evaluated. Like a route-map sequence number, the lowest sequence number is evaluated first.

Defaults

No default behavior or values

Command Modes

Policy-template configuration

Command History

Release	Modification
12.0(24)S	This command was introduced.
12.3(4)T	This command was integrated into Cisco IOS Release 12.3(4)T.
12.2(18)S	This command was integrated into Cisco IOS Release 12.2(18)S.

Usage Guidelines

The inherit peer-policy command is used to configure a peer policy template to inherit the configuration of another peer policy template. Peer policy templates support inheritance and a peer can directly and indirectly inherit up to seven peer policy templates. Inherited peer policy templates are configured with sequence numbers like route maps. An inherited peer policy template, like a route map, is evaluated starting with the inherit statement with the lowest sequence number. However, peer policy templates do not fall through. Every sequence is evaluated. If a BGP policy command is reapplied with a different value, it will overwrite any previous value from a lower sequence number.

---

Note A Border Gateway Protocol (BGP) routing process cannot be configured to be a member of a peer group and to use peer templates for group configurations. You must use one method or the other. We recommend peer templates because they provide improved performance and scalability.

---

Examples

In the following example, a peer policy template named CUSTOMER-A is created. This peer policy template is configured to inherit the configuration from the peer policy templates named PRIMARY-IN and GLOBAL.

Router(config-router)# template peer-policy CUSTOMER-A

Router(config-router-ptmp)# route-map SET-COMMUNITY in

Router(config-router-ptmp)# filter-list 20 in 

Router(config-router-ptmp)# inherit peer-policy PRIMARY-IN 20

Router(config-router-ptmp)# inherit peer-policy GLOBAL 10

Router(config-router-ptmp)# exit-peer-policy

Router(config-router)#

Related Commands

Command	Description
exit peer-policy	Exits policy-template configuration mode and enters router configuration mode.
neighbor inherit peer-policy	Configures a router to send a peer policy template to a neighbor so that the neighbor can inherit the configuration.
show ip bgp template peer-policy	Displays locally configured peer policy templates.
template peer-policy	Creates a peer policy template and enters policy-template configuration mode.

inherit peer-session

To configure a peer session template to inherit the configuration from another peer session template, use the inherit peer-session command in session-template configuration mode. To remove an inherit statement from a peer session template, use the no form of this command.

inherit peer-session template-name

no inherit peer-session template-name

Syntax Description

template-name

Name of the peer session template to inherit.

Defaults

No default behavior or values

Command Modes

Session-template configuration

Command History

Release	Modification
12.0(24)S	This command was introduced.
12.2(18)S	This command was integrated into Cisco IOS Release 12.2(18)S.
12.3(4)T	This command was integrated into Cisco IOS Release 12.3(4)T.

Usage Guidelines

The inherit peer-session command is used to configure a peer session template to inherit the configuration of another peer session template. A peer can be configured with only one peer session template at a time, and that peer session template can contain only one indirectly inherited peer session template. However, each indirectly inherited session template can also contain an indirectly inherited template. So, a peer can directly inherit only one peer session template and indirectly inherit up to seven additional indirectly inherited peer session templates, allowing you to apply up to a maximum of eight inherited peer session configurations.

---

Note If you attempt to configure more than one inherit statement with a single peer session template, an error message will be displayed.

---

Indirectly inherited peer session templates are evaluated first, and the directly applied (locally configured) peer session template is evaluated last. If a general session command is reapplied with a different value, the subsequent value will have priority and overwrite the previous value that was configured in the indirectly inherited template. In other words, an overlapping statement from a local configuration will override the statement from the inherited configuration.

Examples

In the following example, a peer session template named CORE1 is created. This example inherits the configuration of the peer session template named INTERNAL-BGP.

Router(config-router)# template peer-session CORE1

Router(config-router-stmp)# description CORE-123

Router(config-router-stmp)# update-source loopback 1

Router(config-router-stmp)# inherit peer-session INTERNAL-BGP

Router(config-router-stmp)# exit-peer-session 

Router(config-router)#

Related Commands

Command	Description
exit peer-session	Exits session-template configuration mode and enters router configuration mode.
neighbor inherit peer-session	Configures a router to send a peer session template to a neighbor so that the neighbor can inherit the configuration.
show ip bgp template peer-session	Displays locally configured peer session templates.
template peer-session	Creates a peer session template and enters session-template configuration mode.

input-queue

The input-queue command defines the number of received, but not yet processed RIP update packets contained in the Routing Information Protocol (RIP) input queue. Use the input-queue command in router configuration mode. To remove the configured depth and restore the default depth, use the no form of this command.

input-queue depth

no input-queue

Syntax Description

depth

Numerical value associated with the maximum number of packets in the RIP input queue. The larger the numerical value, the larger the depth of the queue. The range is from 0 to 1024. The default is 50.

Defaults

A depth of 50.

Command Modes

Router configuration

Command History

Release	Modification
11.0	This command was introduced.
12.2(33)SRA	This command was integrated into Cisco IOS Release 12.2(33)SRA.

Usage Guidelines

Consider using the input-queue command if you have a high-end router that is sending at high speed to a low-speed router that might not be able to receive at the high speed. Configuring this command will help prevent the routing table from losing information.

Another way to prevent the routing table from losing information is to use the output-delay command to change the interpacket delay for RIP updates.

Examples

The following example sets the depth of the RIP input queue to 100:

router rip

 input-queue 100

Related Commands

Command	Description
output-delay	Changes the interpacket delay for RIP updates sent.

ip as-path access-list

To configure an autonomous system path filter using a regular expression, use the ip as-path access-list command in global configuration mode. To delete the autonomous system path filter and remove it from the running configuration file, use the no form of this command.

ip as-path access-list acl-number permit | deny regexp

no ip as-path access-list acl-number

Syntax Description

acl-number	Number from 1 to 500 that specifies the as-path access-list number.
permit	Permits advertisement based on matching conditions.
deny	Denies advertisement based on matching conditions.
regexp	Regular expression that defines the as-path filter. Note Refer to the "Regular Expressions" appendix in the Cisco IOS Terminal Services Configuration Guide for information about configuring regular expressions.

Defaults

No default behavior or values

Command Modes

Global configuration

Command History

Release	Modification
10.0	This command was introduced.
12.0(22)S	The range of values that can be entered for the acl-number argument was increased from 199 to 500 in Cisco IOS Release 12.0(22)S.
12.2(15)T	The range values that can be entered for the acl-number argument was increased from 199 to 500 in Cisco IOS Release 12.2(15)T.

Usage Guidelines

The ip as-path access-list command is configure an autonomous system path filter. You can apply autonomous system path filters to both inbound and outbound BGP paths. Each filter is defined by the regular expression. If the regular expression matches the representation of the autonomous system path of the route as an ASCII string, then the permit or deny condition applies. The autonomous system path should not contain the local autonomous system number.

Examples

In the following example, an autonomous system path access list (number 500) is defined to configure the router to not advertise any path through or from autonomous system 65535 to the 10.20.2.2 neighbor:

Router(config)# ip as-path access-list 500 deny _65535_ 

Router(config)# ip as-path access-list 500 deny ^65535$ 

Router(config)# ! 

Router(config)# router bgp 50000 

Router(config-router)#  neighbor 192.168.1.1 remote-as 65535 

Router(config-router)#  neighbor 10.20.2.2 remote-as 40000 

Router(config-router)#  neighbor 10.20.2.2 filter-list 1 out 

Router(config-router)#  end 

In the following example, the router is configured to deny all updates with private autonomous system paths:

Router(config)# ip as-path access-list 1 deny (_64[6-9][0-9][0-9]_|_65[0-9][0-9][0-9]_)

Router(config)# ip as-path access-list 1 permit .* 

Related Commands

Command	Description
neighbor distribute-list	Distributes BGP neighbor information as specified in an access list.
neighbor filter-list	Applies a filter list to the specified neighbor.
neighbor prefix-list	Applies a prefix list to the specified neighbor.

ip authentication key-chain eigrp

To enable authentication of Enhanced Interior Gateway Routing Protocol (EIGRP) packets, use the ip authentication key-chain eigrp command in interface configuration mode. To disable such authentication, use the no form of this command.

ip authentication key-chain eigrp as-number key-chain

no ip authentication key-chain eigrp as-number key-chain

Syntax Description

as-number	Autonomous system number to which the authentication applies.
key-chain	Name of the authentication key chain.

Defaults

No authentication is provided for EIGRP packets.

Command Modes

Interface configuration

Command History

Release	Modification
11.2 F	This command was introduced.

Examples

The following example applies authentication to autonomous system 2 and identifies a key chain named SPORTS:

ip authentication key-chain eigrp 2 SPORTS

Related Commands

Command	Description
accept-lifetime	Sets the time period during which the authentication key on a key chain is received as valid.
ip authentication mode eigrp	Specifies the type of authentication used in EIGRP packets.
key	Identifies an authentication key on a key chain.
key chain	Enables authentication of routing protocols.
key-string (authentication)	Specifies the authentication string for a key.
send-lifetime	Sets the time period during which an authentication key on a key chain is valid to be sent.

ip authentication mode eigrp

To specify the type of authentication used in Enhanced Interior Gateway Routing Protocol (EIGRP) packets, use the ip authentication mode eigrp command in interface configuration mode. To disable that type of authentication, use the no form of this command.

ip authentication mode eigrp as-number md5

no ip authentication mode eigrp as-number md5

Syntax Description

as-number	Autonomous system number.
md5	Keyed Message Digest 5 (MD5) authentication.

Defaults

No authentication is provided for EIGRP packets.

Command Modes

Interface configuration

Command History

Release	Modification
11.2 F	This command was introduced.

Usage Guidelines

Configure authentication to prevent unapproved sources from introducing unauthorized or false routing messages. When authentication is configured, an MD5 keyed digest is added to each EIGRP packet in the specified autonomous system.

Examples

The following example configures the interface to use MD5 authentication in EIGRP packets in autonomous system 10:

ip authentication mode eigrp 10 md5

Related Commands

Command	Description
accept-lifetime	Sets the time period during which the authentication key on a key chain is received as valid.
ip authentication key-chain eigrp	Enables authentication of EIGRP packets.
key	Identifies an authentication key on a key chain.
key chain	Enables authentication of routing protocols.
key-string (authentication)	Specifies the authentication string for a key.
send-lifetime	Sets the time period during which an authentication key on a key chain is valid to be sent.

ip bandwidth-percent eigrp

To configure the percentage of bandwidth that may be used by Enhanced Interior Gateway Routing Protocol (EIGRP) on an interface, use the ip bandwidth-percent eigrp command in interface configuration mode. To restore the default value, use the no form of this command.

ip bandwidth-percent eigrp as-number percent

no ip bandwidth-percent eigrp as-number percent

Syntax Description

as-number	Autonomous system number.
percent	Percent of bandwidth that EIGRP may use.

Defaults

50 percent

Command Modes

Interface configuration

Command History

Release	Modification
11.2	This command was introduced.

Usage Guidelines

EIGRP will use up to 50 percent of the bandwidth of a link, as defined by the bandwidth interface configuration command. This command may be used if some other fraction of the bandwidth is desired. Note that values greater than 100 percent may be configured. The configuration option may be useful if the bandwidth is set artificially low for other reasons.

Examples

The following example allows EIGRP to use up to 75 percent (42 kbps) of a 56-kbps serial link in autonomous system 209:

interface serial 0

 bandwidth 56

 ip bandwidth-percent eigrp 209 75

Related Commands

Command	Description
bandwidth (interface)	Sets a bandwidth value for an interface.

ip bgp fast-external-fallover

To configure per-interface fast external fallover, use the ip bgp fast-external-fallover command in interface configuration mode. To remove a per-interface fast external fallover configuration, use the no form of this command.

ip bgp fast-external-fallover [permit | deny]

no ip bgp fast-external-fallover [permit | deny]

Syntax Description

permit	Allows per-interface fast external fallover.
deny	Prevents per-interface fast external fallover.

Defaults

Global fast external fallover is enabled by default in Cisco IOS software.

Command Modes

Interface configuration

Command History

Release	Modification
12.0ST	This command was introduced.
12.1	This command was integrated into Cisco IOS Release 12.1.

Usage Guidelines

The ip bgp fast-external-fallover command is used to configure per-interface fast external fallover, overriding the global configuration. Entering the permit keyword enables fast external fallover. Entering the deny keyword disables fast external fallover. Entering the no form of this command, returns the router to the global configuration.

Examples

The following example enables per-interface fast-external-fallover on interface Ethernet 0/0:

Router(config)# interface ethernet 0/0

Router(config-if)# ip bgp fast-external-fallover permit

Related Commands

Command	Description
bgp fast-external-fallover	Configures global BGP fast external fall over.

ip bgp-community new-format

To configure BGP to display communities in the format AA:NN (autonomous system:community number/4-byte number), use the ip bgp-community new-format command in global configuration mode. To configure BGP to display communities as a 32-bit number, use the no form of this command.

ip bgp-community new-format

no ip bgp-community new-format

Syntax Description

This command has no argument or keywords.

Defaults

BGP communities (also when entered in the AA:NN format) are displayed as a 32-bit numbers if this command is not enabled or if the no form is entered.

Command Modes

Global configuration

Command History

Release	Modification
12.0	This command was introduced.

Usage Guidelines

The ip bgp-community new-format command is used to configure the local router to display BGP communities in the AA:NN format to conform with RFC-1997. This command only affects the format in which BGP communities are displayed; it does not affect the community or community exchange. However, expanded IP community lists that match locally configured regular expressions may need to be updated to match on the AA:NN format instead of the 32-bit number.

RFC 1997, BGP Communities Attribute, specifies that a BGP community is made up of two parts that are each 2 bytes long. The first part is the autonomous system number and the second part is a 2-byte number defined by the network operator.

Examples

In the following example, a router that uses the 32-bit number community format is upgraded to use the AA:NN format:

Router(config)# ip bgp-community new-format 

The following sample output shows how BGP community numbers are displayed when the ip bgp-community new-format command is enabled:

Router# show ip bgp 10.0.0.0

BGP routing table entry for 10.0.0.0/8, version 4

Paths: (2 available, best #2, table Default-IP-Routing-Table)

  Advertised to non peer-group peers:

  10.0.33.35

  35

    10.0.33.35 from 10.0.33.35 (192.168.3.3)

      Origin incomplete, metric 10, localpref 100, valid, external

      Community: 1:1

  Local

    0.0.0.0 from 0.0.0.0 (10.0.33.34)

      Origin incomplete, metric 0, localpref 100, weight 32768, valid, sourced, best 

Related Commands

Command	Description
show ip bgp	Displays entries in the BGP routing table.

ip community-list

To create or configure a Border Gateway Protocol (BGP) community list and to control access to it, use the ip community-list command in global configuration command. To delete the community list, use the no form of this command.

ip community-list {standard | standard list-name {deny | permit} [community-number] [AA:NN] [internet] [local-AS] [no-advertise] [no-export]} | {expanded | expanded list-name {deny | permit} regexp}

no ip community-list standard | expanded | {expanded | standard} list-name

Syntax Description

standard	Configures a standard community list using a number from 1 to 99 to identify one or more permit or deny groups of communities.
standard list-name	Configures a named standard community list.
permit	Permits access for a matching condition.
deny	Denies access for a matching condition.
community-number	(Optional) Specifies a community as a 32-bit number from 1 to 4294967200. A single community can be entered or multiple communities can be entered, each separated by a space.
AA:NN	(Optional) Autonomous system number and network number entered in the 4-byte new community format. This value is configured with with two 2-byte numbers separated by a colon. A number from 1 to 65535 can be entered each 2-byte number. A single community can be entered or multiple communities can be entered, each separated by a space.
internet	(Optional) Specifies the Internet community. Routes with this community are advertised to all peers (internal and external).
no-export	(Optional) Specifies the no-export community. Routes with this community are advertised to only peers in the same autonomous system or to only other subautonomous systems within a confederation. These routes are not advertised to external peers.
local-as	(Optional) Specifies the local-as community. Routes with community are advertised to only peers that are part of the local autonomous system or to only peers within a subautonomous system of a confederation. These routes are not advertised external peers or to other subautonomous systems within a confederation.
no-advertise	(Optional) Specifies the no-advertise community. Routes with this community are not advertised to any peer (internal or external).
expanded	Configures an expanded community list number from 100 to 500 to identify one or more permit or deny groups of communities.
expanded list-name	Configures a named expanded community list.
regexp	Configures a regular expression that is used to specify a pattern to match against an input string. Note Regular expressions can be used only with expanded community lists

Defaults

BGP community exchange is not enabled by default. It is enabled on a per-neighbor basis with the neighbor send-community command.

The Internet community is applied to all routes or prefixes by default, until any other community value is configured with this command or the set community command.

Once a permit value has been configured to match a given set of communities, the community list defaults to an implicit deny for all other community values.

Community values entered in the new format (AA:NN) are converted to 32-bit numbers if the ip bgp-community new-format command is not enabled on the local router.

Defaults

Global configuration

Command History

Release	Modification
10.3	This command was introduced.
12.0	Support for the local-as community was introduced.
12.0(10)S	Named community list support was added.
12.0(16)ST	Named community list support was introduced.
12.1(9)E	Named community list support was integrated into Cisco IOS Release 12.1(9)E.
12.2(8)T	Named community list support was integrated into Cisco IOS Release 12.2(8)T.
12.0(22)S	The maximum number of expanded community list numbers was increased from 199 to 500.
12.2(15)T	The maximum number of expanded community list numbers was increased from 199 to 500.

Usage Guidelines

The ip community-list command is used to configure BGP community filtering. BGP community values are configured as a 32-bit number (old format) or as a 4-byte number (new format). The new community format is enabled when the ip bgp-community new-format command is entered in global configuration mode. The new community format consists of a 4-byte value. The first two bytes represent the autonomous system number, and the trailing two bytes represent a user-defined network number. Named and numbered community lists are supported. BGP community attribute exchange between BGP peers is enabled when the neighbor send-community command is configured for the specified neighbor. The BGP community attribute is defined in RFC-1997 and RFC-1998.

Standard Community Lists

Standard community lists are used to configure well-known communities and specific community numbers. A maximum of 16 communities can be configured in a standard community list. If you attempt to configure more than 16 communities, the trailing communities that exceed the limit are not processed or saved to the running configuration file.

Expanded Community Lists

Expanded community lists are used to filter communities using a regular expression. Regular expressions are used to configure patterns to match community attributes. The order for matching using the * or + character is longest construct first. Nested constructs are matched from the outside in. Concatenated constructs are matched beginning at the left side. If a regular expression can match two different parts of an input string, it will match the earliest part first. For more information about configuring regular expressions, see the Regular Expressions appendix of the Cisco IOS Terminal Services Configuration Guide.

Community List Processing

When multiple values are configured in the same community list statement, a logical AND condition is created. All community values must match to satisfy an AND condition. When multiple values are configured in separate community list statements, a logical OR condition is created. The first list that matches a condition is processed.

Examples

In the following example, a standard community list is configured that permits routes that from network 10 in autonomous system 50000:

Router(config)# ip community-list 1 permit 50000:10 

In the following example, a standard community list is configured that permits only routes from peers in the same autonomous system or from subautonomous system peers in the same confederation:

Router(config)# ip community-list 1 permit no-export 

In the following example, a standard community list is configured to deny routes that carry communities from network 40 in autonomous system 65534 and from network 60 in autonomous system 65412. This example shows a logical AND condition; all community values must match in order for the list to be processed.

Router(config)# ip community-list 2 deny 65534:40 65412:60 

In the following example, a named standard community list is configured that permits all routes within the local autonomous system or permits routes from network 20 in autonomous system 40000. This example shows a logical OR condition; the first match is processed.

Router(config)# ip community-list standard RED permit local-AS 

Router(config)# ip community-list standard RED permit 40000:20 

In the following example, an expanded community list is configured that will deny routes that carry communities from any private autonomous system:

Router(config)# ip community-list 500 deny _64[6-9][0-9][0-9]_|_65[0-9][0-9][0-9]_ 

In the following example, a named expanded community list configured that denies routes from network 1 through 99 in autonomous system 50000:

Router(config)# ip community-list expanded BLUE deny 50000:[0-9][0-9]_ 

Related Commands

Command	Description
match community	Matches a BGP community.
route-map (IP)	Defines the conditions for redistributing routes from one routing protocol into another, or enables policy routing.
set community	Sets the BGP communities attribute.
set comm-list delete	Removes communities from the community attribute of an inbound or outbound update.
show ip bgp community	Displays routes that belong to specified BGP communities.
show ip bgp regexp	Displays routes that match a locally configured regular expression.

ip default-network

To select a network as a candidate route for computing the gateway of last resort, use the ip default-network command in global configuration mode. To remove a route, use the no form of this command.

ip default-network network-number

no ip default-network network-number

Syntax Description

network-number

Number of the network.

Defaults

If the router has a directly connected interface onto the specified network, the dynamic routing protocols running on that router will generate (or source) a default route. For Router Information Protocol (RIP), this is flagged as the pseudonetwork 0.0.0.0; for Interior Gateway Routing Protocol (IGRP), it is the network itself, flagged as an exterior route.

Command Modes

Global configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

The Cisco IOS software uses both administrative distance and metric information to determine the default route. Multiple ip default-network commands can be given. All candidate default routes, both static (that is, flagged by the ip default-network command) and dynamic, appear in the routing table preceded by an asterisk.

If the IP routing table indicates that the specified network number is subnetted and a nonzero subnet number is specified, then the system will automatically configure a static summary route. This static summary route is configured instead of a default network. The effect of the static summary route is to cause traffic destined for subnets that are not explicitly listed in the IP routing table to be routed using the specified subnet.

Examples

The following example defines a static route to network 10.0.0.0 as the static default route:

ip route 10.0.0.0 255.0.0.0 10.108.3.4

ip default-network 10.0.0.0

If the following command was issued on a router not connected to network 10.140.0.0, the software might choose the path to that network as a default route when the network appeared in the routing table:

ip default-network 10.140.0.0

Related Commands

Command	Description
show ip route	Displays the current state of the routing table.

ip dvmrp metric

To configure the metric associated with a set of destinations for Distance Vector Multicast Routing Protocol (DVMRP) reports, use the ip dvmrp metric command in interface configuration mode. To disable this function, use the no form of this command.

ip dvmrp metric metric [route-map map-name] [mbgp] [mobile] [list access-list-number] [protocol process-id] | dvmrp]

no ip dvmrp metric metric [route-map map-name] [mbgp] [mobile] [list access-list-number] [protocol process-id] | dvmrp]

Syntax Description

metric	Metric associated with a set of destinations for DVMRP reports. It can be a value from 0 to 32. A value of 0 means that the route is not advertised. A value of 32 is equivalent to infinity (unreachable).
route-map map-name	(Optional) Names a route map. If you specify this keyword and argument, only the destinations that match the route map are reported with the configured metric. Unicast routes are subject to route map conditions before being injected into DVMRP. Route maps cannot be used for DVMRP routes.
mbgp	(Optional) Configures redistribution of only IP version 4 (IPv4) multicast routes into DVMRP.
mobile	(Optional) Configures redistribution of only mobile routes into DVMRP.
list access-list-number	(Optional) Names an access list. If you specify this keyword and argument, only the multicast destinations that match the access list are reported with the configured metric. Any destinations not advertised because of split horizon do not use the configured metric.
protocol	(Optional) Name of a unicast routing protocol. Available protocols are: bgp, dvmrp, eigrp, isis, mobile, odr, ospf, rip, or static. If you specify these values, only routes learned by the specified routing protocol are advertised in DVMRP report messages.
process-id	(Optional) Process ID number of the unicast routing protocol.
dvmrp	(Optional) Allows routes from the DVMRP routing table to be advertised with the configured metric value, or filtered.

Defaults

No metric value is preconfigured. Only directly connected subnets and networks are advertised to neighboring DVMRP routers.

Command Modes

Interface configuration

Command History

Release	Modification
10.2	This command was introduced.
11.1	The route-map keyword was added.
11.1(20)CC	This mbgp keyword was added.
12.0(7)T	This mbgp keyword was added.

Usage Guidelines

When Protocol Independent Multicast (PIM) is configured on an interface and DVMRP neighbors are discovered, the Cisco IOS software sends DVMRP report messages for directly connected networks. The ip dvmrp metric command enables DVMRP report messages for multicast destinations that match the access list. Usually, the metric for these routes is 1. Under certain circumstances, you might want to tailor the metric used for various unicast routes. This command lets you configure the metric associated with a set of destinations for report messages sent out this interface.

You can use the access-list-number argument in conjunction with the protocol and process-id arguments to selectively list the destinations learned from a given routing protocol.

To display DVMRP activity, use the debug ip dvmrp command.

Examples

The following example connects a PIM cloud to a DVMRP cloud. Access list 1 permits the sending of DVMRP reports to the DVMRP routers advertising all sources in the 172.16.35.0 network with a metric of 1. Access list 2 permits all other destinations, but the metric of 0 means that no DVMRP reports are sent for these destinations.

access-list 1 permit 172.16.35.0 0.0.0.255

access-list 1 deny 0.0.0.0 255.255.255.255

access-list 2 permit 0.0.0.0 255.255.255.255

interface tunnel 0

 ip dvmrp metric 1 list 1

 ip dvmrp metric 0 list 2

The following example redistributes IPv4 multicast routes into DVMRP neighbors with a metric of 1:

interface tunnel 0

 ip dvmrp metric 1 mbgp

Related Commands

Command	Description
debug ip dvmrp	Displays information on DVMRP packets received and sent.
ip dvmrp accept-filter	Configures an acceptance filter for incoming DVMRP reports.

ip extcommunity-list

To create an extended community list to configure Virtual Private Network (VPN) route filtering, use the ip extcommunity-list command in global configuration mode. To delete the extended community list, use the no form of this command.

Global Configuration Mode CLI

ip extcommunity-list expanded-list | expanded list-name {permit | deny} [regular-expression] | standard-list | standard list-name {permit | deny} [rt value] [soo value]

no ip extcommunity-list expanded-list | expanded list-name | standard-list | standard list-name

To enter IP Extended community-list configuration mode to create or configure an extended community-list, use the ip extcommunity-list command in global configuration mode. To delete the entire extended community list, use the no form of this command. To delete a single entry, use the no form in IP Extended community-list configuration mode.

ip extcommunity-list expanded-list | expanded list-name | standard-list | standard list-name

no ip extcommunity-list expanded-list | expanded list-name | standard-list | standard list-name