ECS4660-28F_Management Guide-R03

C HAPTER 51 | IP Routing Commands
Border Gateway Protocol (BGPv4)
– 1860 –
COMMAND USAGE
This command can be used to reduce route flapping. However, the bgp
dampening command can provide more precise control of route flapping.
EXAMPLE
Console(config-router)#neighbor 10.1.1.64 advertisement-interval 20
Console(config-router)#
neighbor allowas-in This command configures the number of times the AS path for a received
route can contain the same AS number. Use the no form to restore the
default setting.
SYNTAX
neighbor {ip-address | group-name} allowas-in [count]
no neighbor {ip-address | group-name} allowas-in
ip-address – IP address of a neighbor.
group-name – A BGP peer group containing a list of neighboring
routers configured with the neighbor peer-group command.
count – Maximum number of times the same AS number can appear
in the AS path of a received route. (Range: 1-10, or 3 if the count is
not undefined)
COMMAND MODE
Router Configuration
DEFAULT SETTING
No repeats allowed
COMMAND USAGE
Under standard routing practices, BGP will not accept a route sent from a
neighbor if the same AS number appears in the AS path more than once.
This could indicate a routing loop, and the route message would therefore
be dropped. However, for purposes of traffic engineering (such as
degrading the preference for a certain path), this command can be used to
configure the number of times the same AS is allowed re-appear in the AS
path of a route received from a neighbor.
EXAMPLE
Console(config-router)#neighbor 10.1.1.64 allowas-in 5
Console(config-router)#