3com MSR 20-20 참조 매뉴얼

You can specify a router ID manually. If not, the system selects an IP address as the 
router ID. The selection sequence is the highest IP address among loopback 
interface addresses; if not available, then the highest IP address of interfaces. It is 
recommended to specify a loopback interface address as the router ID to enhance 
network reliability.

Only when the interface with the selected Router ID or the manual Router ID is 
deleted will the system select another ID for the router.

# Specifies the Router ID as 10.18.4.221.

<Sysname> system-view

[Sysname] bgp 100

[Sysname-bgp] router-id 10.18.4.221 

BGP view/BGP-VPN instance view

None

Use the summary automatic command to enable automatic summarization for 
redistributed subnets.

Use the undo summary automatic command to disable automatic 
summarization.

By default, automatic summarization is disabled.

Note that:

■

Neither the default route nor the routes imported using the network 
command can be summarized automatically.

■

With this feature enabled, BGP limits the subnets redistribution from IGP to 
reduce the size of routing table.

# In BGP view, enable automatic summarization.

<Sysname> system-view

[Sysname] bgp 100

[Sysname-bgp] summary automatic 

# In BGP-VPN instance view, enable automatic summarization (the VPN has been 
created).

<Sysname> system-view

[Sysname] bgp 100