Command Reference Guide

3Com Router 3000 Ethernet Family
Command Reference Guide
Chapter 5 BGP Configuration Commands
3Com Corporation
5-11
Use the undo default med command to restore the default MED value.
Multi-exit discriminator (MED) is an external metric for routes. Different from local
preference, MED is exchanged between ASs and will stay in the AS once it enters the
AS. The smaller an MED is, the better a route is. So the route with a lower MED is
preferred. When a router running BGP obtains several routes with identical destination
address and different next-hops from various external peers, it will select the best route
depending on the MED value. In the case that all other conditions are the same, the
system first selects the route with the smaller MED value as the external route of the
autonomous system.
Example
# Routers RTA and RTB belong to AS100, and router RTC belongs to AS200. RTC is
the peer of RTA and RTB. The network between RTA and RTC is X.25 network and the
network between RTB and RTC is Ethernet. So the MED of RTA can be configured as
25 to allow RTC to select the route transmitted by RTB first.
[3Com -bgp] default med 25
5.1.13 display bgp group
Syntax
display bgp [ multicast | [ vpnv4 { all | route-distinguisher route-distinguisher |
vpn-instance vpn-instance-name } ] ] group [ group-name ]
View
Any view
Parameter
group-name: A specified peer group.
vpn-instance vpn-instance-name: Name of VPN instance.
Description
Use the display bgp group command to view the information of peer groups.
Example
# Display the information of the peer group "aaa".
<3Com > display bgp group aaa
Group : aaa type : external
as-number : 200
members in this group :
10.1.1.1 11.1.1.1
configuration within the group :