3com MSR 20-20 참조 매뉴얼

C

HAPTER

 72: BGP C

ONFIGURATION

 C

OMMANDS

Use the compare-different-as-med command to enable the comparison of the 
MED for paths from peers in different ASs.

Use the undo compare-different-as-med command to disable the 
comparison.

The comparison is disabled by default.

If there are several paths for one destination available, the path with the smallest 
MED is selected.

Do not use this command unless associated ASs adopt the same IGP protocol and 
routing selection method.

# In BGP view, enable to compare the MED for paths from peers in different ASs.

<Sysname> system-view

[Sysname] bgp 100

[Sysname-bgp] compare-different-as-med 

# In BGP-VPN instance view, enable to compare the MED for paths from peers in 
different ASs (The VPN has been created).

<Sysname> system-view

[Sysname] bgp 100

[Sysname-bgp] ipv4-family vpn-instance vpn1

[Sysname-bgp-vpn1] compare-different-as-med 

confederation id as-number

BGP view

as-number: Number of the AS that contains multiple sub-ASs, in the range 1 to 
65535.

Use the confederation id command to configure a confederation ID.

Use the undo confederation id command to remove a specified confederation.

By default, no confederation ID is configured.

Configuring a confederation can reduce IBGP connections in a large AS. You can 
split the AS into several sub-ASs, and each sub-AS remains fully meshed. These 
sub-ASs form a confederation. Key IGP attributes of a route, such as the next hop, 
MED, local preference, are not discarded when crossing each sub-AS. The sub-ASs 
still look like a whole from the perspective of other ASs. This can ensure the 
integrity of the former AS, and solve the problem of too many IBGP connections in 
the AS.