CANOGA PERKINS 9175 Command Reference - Manual (Page 256)

CanogaOS Command Reference
16-11
Router mode
Usage
Multi Exit Discriminator (MED) is used in best path selection by BGP. MED is compared after BGP attributes
weight, local preference, AS-path and origin have been compared and are equal. Enable bgp deterministic
med command on all routers in the local AS, for a correct comparison result. After enabling this command, all
paths for the same prefix are grouped together and arranged according to their MED value.
Based on this comparison, the best path is then chosen.
This command compares MED variable when choosing routes advertised by different peers in the same AS,
to compare MED, when choosing routes from neighbors in different ASs use the bgp always-compare-med
command.
Examples
Switch# configure terminal
Switch(config) router bgp 100
Switch(config-router) bgp deterministic-med
Related Commands
show ip bgp, show ip bgp neighbors
16.16 bgp enforce-first-as
Use this command to enforce the first AS for the eBGP routes.
Use the no parameter with this command to disable this feature.
Command Syntax
(no) bgp enforce-first-as
Command Mode
Router mode
Usage
This command specifies that any updates received from an external neighbor that do not have the neighbor’s
configured Autonomous System (AS) at the beginning of the AS_PATH in the received update must be
denied.
Enabling this feature adds to the security of the BGP network by not allowing traffic from unauthorized
systems.
Examples
Switch# configure terminal
Switch(config)# router bgp 100
Switch(config-router)# bgp enforce-first-as