H3C Technologies H3C S5560 Series Switches - Manual (Page 219)

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Configuring basic BGP
This section describes the basic settings required for a BGP network to run.
Enabling BGP
A router ID is the unique identifier of a BGP router in an AS.
• To ensure the uniqueness of a router ID and enhance availability, specify in BGP view the IP address
of a local loopback interface as the router ID.
• If no router ID is specified in BGP view, the global router ID is used.
• To modify a non-zero router ID of BGP, use the router-id command in BGP view, rather than the
router id command in system view.
• If you specify a router ID in BGP view and then remove the interface that owns the router ID, the
router does not select a new router ID. To select a new router ID, use the undo router-id command
in BGP view.
To enable BGP:
Step Command Remarks
1. Enter system view. system-view N/A
2. Configure a global router ID. router id router-id
By default, no global router ID is
configured, and BGP uses the
highest loopback interface IP
address—if any—as the router ID. If
no loopback interface IP address is
available, BGP uses the highest
physical interface IP address as the
route ID regardless of the interface
status.
3. Enable BGP and enter BGP
view or BGP-VPN instance
view.
• Enable BGP and enter BGP
view:
bgp as-number
• Enable BGP and enter
BGP-VPN instance view:
a. bgp as-number
b. ip vpn-instance
vpn-instance-name
By default, BGP is not enabled.
A router can reside in only one AS,
so the router can run only one BGP
process.
To enter BGP-VPN instance view, the
specified VPN instance must already
exist and have the route distinguisher
(RD) configured. For more
information, see MPLS Configuration
Guide.
4. Configure the router ID.
router-id { router-id |
auto-select }
By default, the global router ID is
used.
The auto-select keyword is
supported only in BGP-VPN instance
view.