H3C Technologies H3C SecPath F1000-E User Manual

Page 812

Advertising
background image

787

Configuring a preferred value for routes from a peer/peer
group

If you both reference a routing policy and use the command peer { ipv6-group-name | ipv6-address }
preferred-value value to set a preferred value for routes from a peer, the routing policy sets the specific

preferred value for routes matching it. If the preferred value in the routing policy is zero, the routes use the

value set with the peer { ipv6-group-name | ipv6-address } preferred-value value command. For how to

use a routing policy to set a preferred value, see the command peer { group-name | ipv6-address }
route-policy route-policy-name { import | export } in this chapter, and the command apply

preferred-value preferred-value in

Network Management Command Reference.

To configure a preferred value for routes from a peer/peer group:

Step Command

Remarks

1.

Enter system view.

system-view

N/A

2.

Enter BGP view.

bgp as-number

N/A

3.

Enter IPv6 address family view
or IPv6 BGP-VPN instance

view.

ipv6-family [ vpn-instance
vpn-instance-name ]

N/A

4.

Configure a preferred value
for routes received from an

IPv6 peer/peer group.

peer { ipv6-group-name |
ipv6-address
} preferred-value

value

By default, the preferred value is 0.

Specifying the source interface for establishing TCP
connections

IPv6 BGP uses TCP as the transport layer protocol. By default, IPv6 BGP uses the outgoing interface of the

optimal route to a peer/peer group as the source interface for establishing TCP connections to the

peer/peer group.
To establish a BGP connection, you need to specify on the local router the source interface for

establishing the TCP connection to the peer on the peering BGP router; otherwise, the local BGP router
may fail to establish TCP connection to the peer when you use the outgoing interface of the best route as

the source interface.
If an IPv6 BGP router has multiple links to a peer, and the source interface fails, IPv6 BGP has to

reestablish TCP connections, causing network oscillation. To enhance stability of IPv6 BGP connections,
H3C recommends using a loopback interface as the source interface.
To specify the source interface for establishing TCP connections to a BGP peer or peer group:

Step Command

Remarks

1.

Enter system view.

system-view

N/A

2.

Enter BGP view.

bgp as-number

N/A

3.

Enter IPv6 address family

view.

ipv6-family

N/A

Advertising