# BGP Address-Family (IPv4/IPv6) Configuration Mode Commands

The Border Gateway Protocol (BGP) Address-Family (IPv4/IPv6) Configuration Mode is used to configure the IPv4 and IPv6 address family information.

IMPORTANT:

The commands or keywords/variables that are available are dependent on platform type, product version, and installed license(s).
end

Exits the current configuration mode and returns to the Exec mode.
Product:

All
Privilege:

Security Administrator, Administrator
Syntax

    end

Usage:

Use this command to return to the Exec mode.
exit

Exits the current mode and returns to the parent configuration mode.
Product:

All
Privilege:

Security Administrator, Administrator
Syntax

    exit

Usage:

Use this command to return to the parent configuration mode.

maximum-paths

Controls the maximum number of parallel external BGP (eBGP) or internal BGP (iBGP) routes that can be installed in a routing table.
Platform:

ASR 5000

ASR 5500
Product:

All
Privilege:

Security Administrator, Administrator

Syntax

    [ no ] maximum-paths { ebgp num_paths | ibgp num_paths }

no

Disables the above command.
maximum-paths ebgp num_paths

Specifies the maximum number of parallel External Border Gateway Protocol routes as an integer from 1 through 10.
maximum-paths ibgp num_paths

Specifies the maximum number of parallel Internal Border Gateway Protocol routes as an integer from 1 through 10.

IMPORTANT:

If configured under the router-bgp-mode, multipath is enabled only for the prefixes learnt in the default-vrf. There is no support for vpnv4 prefixes even though multipath is turned on for the default-vrf.

If configured under the address-family-vrf-mode, multipath is enabled only for prefixes learnt in the vrf.

Usage

Use this command to forward packets over multiple paths. User can control the maximum number of parallel eBGP routes that can be installed in a routing table. Enabling multipath does not affect the best path selection in BGP. If multipath is enabled, all the paths with the same weight, local-preference, as-path length, origin, and multi-exit discriminator (MED) as the best path are added to the routing table.

Example

Example

The following command disables forward of packets over multiple paths:

    no maximum-paths ebgp

neighbor

Configures the IPv4/IPv6 Address Family for BGP routers that interconnect to non-broadcast networks.
Platform:

ASR 5000

ASR 5500
Product:

All
Privilege:

Security Administrator, Administrator
Syntax

    [ no ] neighbor ip_address { activate | advertisement-interval adv_time | capability
    graceful-restart | default-originate [ route-map  map_name ] | distribute-list dist_list { in | out } | ebgp-multihop [ max-hop number ] encrypted
    password encryp_password fall-over bfd multihop | filter-list filt_list { in | out } | max-prefix max_num [ threshold thresh_percent ] [ warning-only ] next-hop-self | password password | remote-as AS_num | remove-private-AS
     | restart-time rest_time | route-map map_name { in | out} | send-community { both | extended | standard } | shutdown | srp-activated-soft-clear | timers { connect-interval connect_interval [ keepalive-interval keepalive_interval  holdtime-interval holdtime_interval [ min-peer-holdtime-interval min_peer_hold_interval ] ] | keepalive-interval keepalive_interval holdtime-interval holdtime_interval { connect-interval connect_interval | min-peer-holdtime-interval min_peer_hold_interval [ connect-interval connect_interval  ] } } | update-source ip_address | weight value }

no

Delete the specified parameter from the router configuration.
neighbor ip_address

Specifies the IP address of a BGP neighbor. ip_address must be in IPv4 dotted-decimal or IPV6 colon-separated-hexadecimal notation.
activate

Enables the exchange of routes with this neighbor.
advertisement-interval adv_time

Specifies the minimum interval (in seconds) between sending BGP routing updates.

adv_time must be an integer from 0 through 600. Default: 30
capability graceful-restart

Configures graceful re-start attributes.
default-originate [ route-map map_name ]

Specifies the default originate routes to this neighbor

route-map map_name: Specifies the route-map that contains the criteria to originate default routes. map_name must be the name of an existing route-map in the current context.
distribute-list dist_list { in | out }

Filters updates to and from this neighbor based on a route access list. Default: No filtering is performed. dist_list is the name or number of an existing route-access-list.

in: Indicates that incoming advertised routes should be filtered.

out: Indicates that outgoing advertised routes should be filtered.
ebgp-multihop [ max-hop number ]

Allows eBGP neighbors that are not on directly connected networks.

max-hop number: Specifies the maximum number of hops allowed to reach a neighbor as an integer from 1 through 255. Default hop count: 255
encrypted password encryp_password

Specifies the encrypted password that is used only inside configuration files. This is an alphanumeric string of 1 through 24 characters.
fall-over bfd multihop

Supports Bidirectional Forwarding Detection (BFD) multihop for fallover.
filter-list filt_list {in | out}

Establishes BGP filters based on an autonomous system (AS) path access list. filt_list is name of an existing AS path access list.

in: Indicates that incoming advertised routes will be filtered.

out: Indicates that outgoing advertised routes will be filtered.
max-prefix max_num [ threshold thresh_percent ] [ warning-only ]

Specifies the maximum number of prefixes accepted from this peer. When the maximum is exceeded the neighbor connection is reset. max_num is an integer from 1 through 4294967295. Default: No maximum prefix limit.

threshold thresh_percent: Specifies a percentage value of when the BGP table is full. When this value is reached peer warnings are sent to the neighbor. thresh_percent must be an integer from 1 through 100.

warning-only: Specifies that only a warning message is sent when the limit is exceeded. The neighbor connection is not reset
next-hop-selfip_address

Disables the next hop calculation for this neighbor.
passwordpassword

Sets a password expressed as an alphanumeric string of 1 through 24 characters.
remote-as AS_num

Specify the AS number of the BGP neighbor as an integer from 1 through 4294967295.
remove-private-AS

Removes the private AS number from outbound updates. Default: Do not remove the private AS number.
restart-time rest_time

Specifies the maximum time (in seconds) required to for neighbor to restart as an integer from 1 through 3600.
route-map map_name { in | out }

Applies a route map to the neighbor. map_name must be the name of an existing route-map in the current context.

in: Indicates that the route map applies to incoming advertisements.

out: Indicates that the route map applies to outgoing advertisements.
send-community{ both | extended | standard }

Sends the community attributes to a peer router (neighbor).

both:Sends standard and extended community attributes

extended:Sends extended community attributes.

standard:Sends standard community attributes.
shutdown

Administratively shuts down this neighbor. This disables exchanging routes or configuring parameters for this neighbor.

srp-activated-soft-clear

Enables BGP updates when SRP-enabled resources are modified.
timers { [ connect-interval connect_interval ] | [ keepalive-interval keepalive_interval holdtime-interval holdtime_interval ] }

Sets BGP timers for the specified neighbor.

connect-interval connect_interval: Specifies the connect timer (in seconds) as an integer from 0 through 65535. The default is 60 seconds.

keepalive-interval keepalive_interval: Specifies the frequency (in seconds) at which the current BGP router sends keepalive messages to its neighbor. keep_time must be an integer from 0 through 65535. The default is 30 seconds.

holdtime-interval holdtime_interval: Specifies the interval (in seconds) the router waits for a keepalive message before declaring a neighbor dead. hold_time must be an integer from 0 through 65535. The default is 90 seconds.

min-peer-holdtime-interval min_peer_hold_interval: Specifies the minimum acceptable hold time (in seconds) from peer for a keepalive message before declaring a neighbor dead. min_peer_hold_interval must be an integer from 0 through 65535. The default is 90 seconds.
update-source ip_address

Binds the specified IP address to the BGP socket that is used to communicate to the peer. ip_address is an IPv4 address in dotted-decimal notation.

In most cases you should set the update-source address to the address of the loopback interface in the current context. By doing this, the TCP connection does not go down until there is no route for the loopback address in the peering router.
weight value

Sets the default weight for routes from this neighbor as an integer from 0 through 65535. Default: 0
Usage:

Use this command to set parameters for communication with a specified neighbor. The chassis supports a maximum of 64 peers per context.

IMPORTANT:

A remote AS number must be specified for a neighbor before other parameters can be configured.
Example:
The following command specifies that the neighbor at the IP address 192.168.100.25 has an AS number of 2000:

    neighbor 192.168.100.25
    remote-as 2000

The following command allows BGP neighbors that are a maximum of 27 hops away:

    neighbor 192.168.100.25
    ebgp-multihop max-hop 27

The following command sets the minimum interval between sending routing updates to 3 minutes (180 seconds):

    neighbor 192.168.100.25
    advertisement-interval 180

The following command sets the default weight for all routes from the specified neighbor to 100:

    neighbor 192.168.100.25
    weight 100

network

Configures and specifies a network to announce via BGP.
Platform:

ASR 5000

ASR 5500
Product:

All
Privilege:

Security Administrator, Administrator
Syntax

    [ no ] network ip_address/mask [ route-map map_name ]

no

Delete the specified network from the configuration for the BGP router.
network ip_address/mask

Specifies the IP address and netmask bits for the network to announce via BGP. ip_address is a network IP address in IPV4 dotted-decimal notation and mask is the number of subnet bits, representing a subnet mask in CIDR. These must be entered in the IPv4 dotted-decimal notation/subnet bits format.
route-map map_name

Filter routes through the specified route map before announcing the network. map_name specifies the name of the route-map to use as an alphanumeric string of 1 through 79 characters.
Usage:

Use this command to specify a network to announce via BGP.
Example:
The following command announces the network 192.168.0.0 with a netmask of 16 via BGP:

    network 192.168.0.0/16

The following command removes the network from the BGP router configuration:

    no network 192.168.0.0/16

redistribute

Redistributes routes into BGP from another protocol as BGP neighbors.
Platform:

ASR 5000

ASR 5500
Product:

All
Privilege:

Security Administrator, Administrator
Syntax

    [ no ] redistribute { connected | ospf | rip | static } [ route-map map_name ]

no

Remove the specified redistribution parameters from the BGP router configuration.
redistribute connected

Specifies that connected routes will be redistributed.
redistribute ospf

Specifies that Open Shortest Path First (OSPF) routes will be redistributed
redistribute rip

Specifies that Routing Information Protocol (RIP) routes will be redistributed. (RIP is not supported at this time.)
redistribute static

Specifies that static routes will be redistributed.
route-map map_name

Filters routes through the specified route map before redistribution. map_name specifies the name of the route-map to use as an alphanumeric string of 1 through 79 characters.
Usage:

Use this command to specify what routes this BGP router should redistribute into BGP.
Example:
The following command redistributes OSPF routes after filtering them through the route map named Map1:

    redistribute ospf route-map Map1

The following command removes the redistribution of OSPF routes from the router’s configuration:

    no redistribute ospf
    route-map Map1