Border Gateway Protocol Configuration Mode Commands


Border Gateway Protocol Configuration Mode Commands
 
 
The Border Gateway Protocol (BGP) Configuration Mode is used to configure properties for BGP-4 routing.
 
Important: The commands or keywords/variables that are available are dependent on platform type, product version, and installed license(s).
 
address-family ipv4
Configures the IPv4 Address Family information for the specified BGP AS number. Optionally it also enables the VRF routing information, if specified.
Product
PDSN, GGSN
Privilege
Security Administrator, Administrator
Syntax
address-family ipv4 [ vrf vrf_name]
[no] address-family ipv4 vrf vrf_name}
no
This keyword removes the configured IPv4 address family VRF mode for specific BGP AS number.
vrf vrf_name
This optional keyword enables the exchange of VRF routing informaiton. When this keyword is specified with this command then the address family mode changed to VRF address family mode for specific BGP AS number.
Important: The route distinguigher id must be configured for this VRF name through route-distinguisher command in BGP VRF Configuration mode, before using this keyword.
Usage
Use this command to configure the IPv4 BGP address family configuration parameters for BGP router and optionally enables the exchange of VRF routing information. This command is also used to switch the command mode to enter the BGP Address Family Configuration Mode.
Use of address-family ipv4 command swithces the command mode to BGP Address Family Configuraiton Mode and prompt will be changed to the following:
[context_name>]host_name(config-bgp-af-v4)#
Use of address-family ipv4 vrf vrf_name command swithces the command mode to BGP Address Family Configuraiton Mode and prompt will be changed to the following:
[context_name>]host_name(config-bgp-af-vrf)#
Example
Use following command to enter the IPv4 BGP Address-Family configuration mode:
address-family ipv4
Use following command to enter the IPv4 VRF BGP Address-Family configuration mode for exchange of VRF routing information from VRF route_vrf1:
address-family ipv4 vrfroute_vrf1
 
address-family ipv6
Configures the IPv6 Address Family information for the specified BGP AS number.
Product
PDSN, GGSN
Privilege
Security Administrator, Administrator
Syntax
address-family ipv6
Usage
Use this command to configure the IPv6 BGP address family configuration parameters for BGP router. This command is also used to switch the command mode to enter the BGP Address Family Configuration Mode.
Use of address-family ipv6 command swithces the command mode to BGP Address Family Configuraiton Mode and prompt will be changed to the following:
[context_name>]host_name(config-bgp-af-v6)#
Example
Use the following command to enter the IPv6 BGP Address-Family configuration mode:
address-family ipv6
 
address-family vpnv4
Configures the VPNv4 Address Family information for the specified BGP AS number.
Product
PDSN, GGSN
Privilege
Security Administrator, Administrator
Syntax
address-family vpnv4
Usage
Use this command to configure the VPNv4 address family configuration parameters for BGP router. This command is also used to switch the command mode to enter the BGP Address Family Configuration Mode.
Use of address-family vpnv4 command swithces the command mode to BGP Address Family Configuraiton Mode and prompt will be changed to the following:
[context_name>]host_name(config-bgp-af-vpnv4)#
Example
Use the following command to enter the BGP Address-Family configuration mode for VPNv4 address parameters:
address-family vpnv4
 
distance
Define the administrative distance for routes. The administrative distance is the default priority for a specific route or type route.
Product
HA
Privilege
Security Administrator, Administrator
Syntax
distance { admin distance prefix prefix_addr [ route-access-list list_name ] | bgp external ebgp_dist internal ibgp_dist local local_dist }
no distance { admin distance prefix prefix_addr [ route-access-list list_name ] | bgp [ external ebgp_dist internal ibgp_dist local local_dist ] }
no
Remove the specified administrative distance for the specific route.
admin distance prefix prefix_addr [ route-access-list list_name ]
This keyword sets the administrative distance to a specified value for routes with a specific IP prefix. If you also specify a route access list, the IP prefix must match the rules of that access list.
admin distance: The administrative distance that you want to apply to the IP prefix. distance must be an integer from 1 through 254.
prefix prefix_addr: The IP prefix of routes that should have the admin distance applied. prefix_addr must be an IPv4 address (in dotted-decimal notation) and the number of subnet bits, representing the subnet mask in shorthand (1.1.1.1/24).
route-access-list list_name: Define the name of a route access list that defines for which routes the administrative distance should be set.
bgp external ebgp_dist internal ibgp_dist local local_dist
This keyword sets the administrative distance for internal (IBGP), external (EBGP) and local routes.
external ebgp_dist: Set the administrative distance for EBGP routes. ebgp_dist must be an integer from 1 through 254.
internal ibgp_dist: Set the administrative distance for IBGP routes. ibgp_dist must be an integer from 1 through 254.
local local_dist: Set the administrative distance for local routes. local_dist must be an integer from 1 through 254.
Usage
Use this command to set the administrative distance for specific routes to values that you specify. These values are only applied to the current router.
Example
Use the following command to set the administrative distance to 100 for all routes that have an IP prefix of 192.168.0.0 with a netmask of 16 and are specified in a remote access list named racl1:
distance admin 100 prefix 192.168.0.0/16 route-access-list racl1
 
end
Exits the current configuration mode and returns to the Exec mode.
Product
HA
Privilege
Security Administrator, Administrator
Syntax
end
Usage
Return to the Exec mode.
 
enforce-first-as
Enforce the first Autonomous System (AS) for Exterior Border Gateway Protocol (EBGP) routes. As stated in RFC1930; “An AS is a connected group of one or more Internet Protocol prefixes run by one or more network operators which has a single and clearly defined routing policy.”
Product
HA
Privilege
Security Administrator, Administrator
Syntax
enforce-first-as
Usage
Use this command to enforce the use of the first AS for EBGP routes.
Example
Use the following command to enable this functionality:
enforce-first-as
 
exit
Exits the current configuration mode and returns to the global configuration mode.
Product
HA
Privilege
Security Administrator, Administrator
Syntax
exit
Usage
Return to the context configuration mode.
 
ip vrf
This command adds a preconfigured IP VRF context instance to the BGP ASN and configures the BGP attributes and related parameters to the VRF. This command also switches the command mode to BGP VRF Configuration mode.
Product
PDSN, GGSN
Privilege
Security Administrator, Administrator
Syntax
[no] ip vrf vrf_name
no
Removes an associated IP VRF from specified BGP AS number and other configured parameters.
vrf_name
Specifies the IP VRF context configured in the Context configuration mode and to be associated with a BGP AS number.
vrf_name must be a string from 1 to 79 identifying an existing instance.
Usage
Use this command to associate the specified IP VRF context instance to the BGP AS number and configures the BGP attributes and related parameters to the VRF. This command also switches the command mode to BGP VRF Configuration mode.
This command swithces the command mode to BGP IP VRF Configuraiton Mode and prompt will be changed to the following:
[context_name>]host_name(config-bgp-vrf)#
Example
Use the following command associates the pre-defined VRF context instance router_mpls to this BGP AS number:
ip vrf router_mpls
 
neighbor
This command configures BGP routers that interconnect to non-broadcast networks. Note that a remote AS number must be specified for a neighbor before other parameters can be configured.
Product
HA
Privilege
Security Administrator, Administrator
Syntax
[no] neighbor ip_address {activate|advertisement-interval adv_time | default-originate [route-map map_name] | distribute-list dist_list {in | out}| ebgp-multihop [max-hop number] | filter-list filt_list {in | out}| max-prefix max_num [threshold thresh_percent] [warning-only] | remote-as AS_num| remove-private-AS | route-map map_name {in | out} | shutdown | timers {[connect-interval conn_time] | [keepalive-interval keep_time Holdtime-interval hold_time]}| update-source ip_address | weight value}
no
Delete the specified parameter from the router configuration.
activate
Enable the exchange of routes with this neighbor.
advertisement-interval adv_time
The minimum interval, in seconds, between sending BGP routing updates.
Default: 30
adv_time must be an integer from 0 through 600.
default-originate [route-map map_name]
Originate default 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}
Filter updates to and from this neighbor based on a route access list.
Default: No filtering is performed.
dist_list: 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]
Allow EBGP neighbors not on directly connected networks.
Default hop count: 255
max-hop number: The maximum number of hops allowed to reach a neighbor. number must be an integer from 1 through 255.
filter-list filt_list {in | out}
Establish BGP filters based on an AS path access list
filt_list: The 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]
The maximum number of prefixes accepted from this peer. When the maximum is exceeded the neighbor connection is reset.
Default: No maximum prefix limit.
max_num: Specifies the maximum number of prefixes permitted. This must be an integer from 1 through 4294967295.
threshold thresh_percent: A percentage value which specifies that when the BGP table is the specified percentage full from this peer warnings are sent to the neighbor. thresh_percent must be an integer from 1 through 100.
warning-only: This keyword specifies that only a warning message is sent when the limit is exceeded. The neighbor connection is not reset
remote-as AS_num
Specify the AS number of the BGP neighbor.
AS_num: The neighbor’s autonomous system number. must be an integer from 1 through 65535.
remove-private-AS
Remove the private AS number from outbound updates.
Default: Do not remove the private AS number.
route-map map_name {in | out}
Apply a route map to the neighbor.
map_name: Specifies the route-map apply. 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.
shutdown
Administratively shut down this neighbor. This disables exchanging routes or configuring parameters for this neighbor.
timers {[connect-interval conn_time] | [keepalive-interval keep_time Holdtime-interval hold_time]}
BGP timers for the specified neighbor.
connect-interval conn_time: Specifies the connect timer in seconds. conn_time must be an integer from 0 through 65535. The default is 60 seconds.
keepalive-interval keep_time: 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 hold_time: 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.
update-source ip_address
use this keyword to bind 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
This command sets the default weight for routes from this neighbor.
Default: 0
value: This must be an integer from 0 through 65535.
Usage
Use this command to set parameters for communication with a specified neighbor. The chassis supports a maximum of 64 peers per context.
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
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
Specify a network to announce via BGP
Product
HA
Privilege
Security Administrator, Administrator
Syntax
network ip_adrress/mask [ route-map map_name ]
no network ip_adrress/mask [ route-map map_name ]
no
Delete the specified network from the configuration for the BGP router.
ip_adrress/mask
Specifies the IP address and netmask bits for the network to announce via BGP. ip_address is a network IP address (in dotted-decimal notation) and mask is the number of subnet bits, representing a subnet mask in shorthand. These must be entered in the dotted-decimal notation/subnet bits format (1.1.1.1/24).
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 and must be specified as a string of 1 through 79 alphanumeric 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
This command redistributes routes into BGP. This means that any routes from another protocol are redistributed to BGP neighbors using the BGP protocol.
Product
HA
Privilege
Security Administrator, Administrator
Syntax
redistribute { connected | ospf | rip | static } [ route-map map_name ]
no
Remove the specified redistribution parameters from the BGP router configuration.
connected
Specifies that connected routes will be redistributed.
ospf
Specifies that OSPF routes will be redistributed
rip
Specifies that RIP routes will be redistributed. (RIP is not supported at this time.)
static
Specifies that static routes will be redistributed.
route-map map_name
Filter routes through the specified route map before redistribution. map_name specifies the name of the route-map to use and must be specified as a string of 1 through 79 alphanumeric 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
 
router-id
Override the configured router identifier (peers will reset).
Product
HA
Privilege
Security Administrator, Administrator
Syntax
router-id ip_address
no router-id [ ip_address ]
no
Remove the specified router ID from the router’s configuration and use the default router ID.
ip_address
The IP address to use as the BGP router ID. ip_address must be an IPv4 address in dotted decimal notation (###.###.###.###).
Usage
Use this command to configure a specific router ID that overrides the default.
Example
The following command sets the router ID to 192.168.100.25:
router-id 192.168.100.25
 
scan-time
Configure background scanner interval. The background scanner scans routers for next hop validation.
Product
HA
Privilege
Security Administrator, Administrator
Syntax
scan-time time
no scan-time
no
Remove the user specified scan time from the router’s configuration. The scan time is reset to the default value.
time
Default: 60
The amount of time, in seconds, to wait between background scans to determine next-hop validity. time must be an integer from 5 through 60.
Usage
Use this command to set the background scanner interval for the BGP router.
Example
The following command sets the background scanner interval to 30 seconds:
scan-time 30
 
timers
This command configures BGP routing timers.
Product
HA
Privilege
Security Administrator, Administrator
Syntax
timers bgp Keepalive-interval interval Holdtime-interval time [ Min-peer-holdtime-interval ] time
no timers bgp
no
Remove the user specified timer values from the router’s configuration. The timer values are reset to the default values.
Keepalive-interval interval
Default: 30
The interval, in seconds, to wait between sending keepalive packets. Must be an integer from 0 through 65535.
Holdtime-interval time
Default: 90
The interval, in seconds, after which the neighbor is considered dead if keepalive messages are not received. Must be an integer from 0 through 65535.
Min-peer-holdtime-interval time
Default: 0
The interval, in seconds, that is the minimum acceptable hold time from a neighbor. Must be an integer from 0 through 65535. The default is 0 so that there is no restriction on the hold time received in an OPEN message from the peer.
Usage
Use this command to configure the how long to wait between sending keepalive packets and how long to wait for a keepalive before considering a a neighbor dead.
Example
The following command sets the keepalive interval to 2 minutes and the holdtime interval to 3 minutes:
timers bgp Keepalive-interval 120 Holdtime-interval 180 Min-peer-holdtime-interval 0
 
 

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