R2511-HP MSR Router Series Layer 3 - IP Routing Configuration Guide(V5)

184
Ste
p
Command Remarks
6. Enable the default use of IPv4
unicast address family for the
peers that are established
using the peer as-number
command.
default ipv4-unicast
Optional.
Enabled by default.
This command is not supported in
BGP-VPN instance view.
7. Enable a peer.
peer ip-address enable
Optional.
Enabled by default.
8. Configure a description for a
peer group.
peer group-name description
description-text
Optional.
By default, no description is
configured for the peer group.
To configure an EBGP peer group by using Method 3:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter BGP view or BGP-VPN
instance view.
• Enter BGP view:
bgp as-number
• Enter BGP-VPN instance view:
a. bgp as-number
b. ipv4-family vpn-instance
vpn-instance-name
Use either method.
3. Create an EBGP peer group.
group group-name external N/A
4. Add a peer into the EBGP
peer group.
peer ip-address group group-name
as-number as-number
N/A
5. Enable a peer.
peer ip-address enable
Optional.
Enabled by default.
6. Configure a description for a
peer group.
peer group-name description
description-text
Optional.
By default, no description is
configured for the peer group.
Specifying the source interface for TCP connections
By default, BGP uses the output interface of the optimal route to a peer or peer group as the source
interface for establishing TCP connections to the peer or peer group, and it uses the primary IP address
of the output interface as the source IP address of TCP connections. You can change the source interface
(primary IP address) for TCP connections in the following scenarios:
• If the peer's IP address belongs to an interface indirectly connected to the local router, you must
specify that interface as the source interface for TCP connections on the peer. For example, interface
A on the local end is directly connected to interface B on the peer. If you execute the peer x.x.x.x
as-number as-number command in which x.x.x.x is not the IP address of interface B on the local
end, you must use the peer connect-interface command on the peer to specify the interface whose
IP address is x.x.x.x as the source interface for establishing a TCP connection.
• On a BGP router that has multiple links to a peer, if the source interface fails, BGP has to reestablish
TCP connections. To avoid this problem, use a loopback interface as the source interface.