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.
Privilege
Security
Administrator, Administrator
Mode
Exec > Global
Configuration > Context Configuration > BGP Configuration
configure > context
context_name
> router bgp
as_number
Entering the above
command sequence results in the following prompt:
[context_name]host_name(config-bgp)#
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 encrypted password | fall-over bfd [ multihop ] [ associate ] | 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 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.
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
Enable the exchange
of routes with this neighbor.
advertisement-interval
adv_time
The minimum interval
(in seconds) between sending BGP routing updates.
adv_time must
be an integer from 0 through 600. Default: 30
Note |
The advertisement-interval must be explicitly configured for an
address-family so that it can take effect for that address-family. By default
it will be applicable only for the IPv4 address-family. Specify the address
family via the
address-family command. You can then set
the neighbor advertisement-interval in the address family configuration mode.
|
capability graceful-restart
Configures BGP
graceful restart attributes.
default-originate [ route-map
map_name ]
Enables the
origination of 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
}
Filters updates to
and from this neighbor based on a route access list.
dist_list :
The name or number of an existing route-access-list. Default: No filtering is
performed.
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.
number must
be an integer from 1 through 255. Default hop count: 255
encrypted password
encrypted
password
Specifies an
encrypted password that is used only inside configuration files. This should be
an alphanumeric string of 1 through 523 characters.
fall-over bfd [ multihop ] [ associate ]
Enables Bidirectional Fowarding Detection (BFD) multihop support for fallover.
This command adds
or modifies a session in BFD for the BGP peer. If there is an existing session
in BFD (same source-address/destination address), BGP
or OSPF
protocol will be added to the list of clients for the BFD session.
BGP
or OSPF
will then be notified when there is a change in the BFD session
state.
If there is no
such BFD session, a new session is added in BFD. For MH-BFD, the session
inherits the parameters including min-tx, min-rx, multiplier and authentication
from the multihop-peer configuration in BFD by matching the destination
address. If the parameters (interval) are not configured in BFD, then the BFD
session will be in Admin-down state.
BGP adds a session
in BFD only when the BGP peer is Established state. If there is a state
transition in bgp where the peer is no longer in established state, then the
bfd session is deleted. It will be added again, once the peer comes back to
Established state.
When used, the associate keyword associates BGP and BFD neighbors. BGP peers come up only when the BFD session is up.
filter-list
filt_list {
in |
out
}
Establishes BGP
filters based on an AS path access list.
filt_list is
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 ] : Specifies a percentage value of when the BGP
table is full. When this value is reached, peer warnings are sent to the
neighbor and the neighbor connection is reset.
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-self
Disables the next
hop calculation for this neighbor.
password
password
Specifies a
password that is only used inside configuration files. This should be an
alphanumeric string of 1 through 24 characters.
remote-as
AS_num
Specify the AS
number of the BGP neighbor.
AS_num : Specifies the neighbor's AS number as an
integer from 1 through 65535.
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 for a neighbor to restart.
rest_time
must be an integer between 1 and 3600.
route-map
map_name
{ in | out
}
Applies a route
map to the neighbor.
map_name i s
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 extended and standard 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 Service Redundancy Protocol SRP-enabled resources are modified.
timers { [ connect-interval
conn_time ] | [ keepalive-interval
keep_time
holdtime-interval
hold_time ] }
Specifies BGP
timers for this 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
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.
value must be
an integer from 0 through 65535. Default: 0
Usage Guidelines
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
(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