H3C Technologies H3C S12500 Series Switches - Manual (Page 374)

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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 or peer group.
peer { group-name |
ipv6-address } preferred-value
value
Optional.
By default, the preferred value is 0.
The IPv6 BGP-VPN instance view
does not support the group-name
argument.
Specifying the source interface for establishing TCP
connections
IPv6 BGP uses TCP as the transport layer protocol. By default, IPv6 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.
To establish a BGP connection, 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 might fail to establish
TCP connection to the peer when using the output 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 that you use 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
4. Specify the source interface
for establishing TCP
connections to an IPv6 BGP
peer or peer group.
peer { group-name |
ipv6-address } connect-interface
interface-type interface-number
By default, IPv6 BGP uses the
output interface of the best route to
the IPv6 BGP peer or peer group as
the source interface for
establishing a TCP connection.
Allowing the establishment of an indirect EBGP connection
In general, direct links must be available between EBGP peers. If not, you can use the peer
ebgp-max-hop command to establish a multi-hop TCP connection in between. However, you need not
use this command for direct EBGP connections with loopback interfaces.
To allow the establishment of a non-direct EBGP connection: