H3C Technologies H3C S7500E Series Switches - Manual (Page 343)

11-14
To do… Use the command… Remarks
Allow the local AS number to
appear in AS_PATH of routes from
a peer/peer group and specify the
repeat times
peer { ipv6-group-name |
ipv6-address } allow-as-loop
[ number ]
Optional
Not allowed by default
Specify a fake AS number for an
IPv6 peer/peer group
peer { ipv6-group-name |
ipv6-address } fake-as as-number
Optional
Not specified by default.
Disable IPv6 MBGP from
considering the AS_PATH during
best route selection
bestroute as-path-neglect
Optional
Enabled by default.
Configure to carry only the public
AS number in updates sent to a
peer/peer group
peer { ipv6-group-name |
ipv6-address } public-as-only
Optional
By default, IPv6 BGP updates
carry private AS number.
Substitute the local AS number for
the AS number of an IPv6
peer/peer group identified in the
AS_PATH attribute
peer { ipv6-group-name |
ipv6-address } substitute-as
Optional
Not substituted by default
Tuning and Optimizing IPv6 BGP Networks
This section describes configurations of IPv6 BGP timers, IPv6 BGP connection soft reset and the
maximum number of load balanced routes.
z IPv6 BGP timers
After establishing an IPv6 BGP connection, two routers send keepalive messages periodically to each
other to keep the connection. If a router receives no keepalive message from the peer after the
holdtime elapses, it tears down the connection.
When establishing an IPv6 BGP connection, the two parties compare their holdtimes, taking the
shorter one as the common holdtime. If the holdtime is 0, neither keepalive massage is sent, nor
holdtime is checked.
z IPv6 BGP connection soft reset
After modifying a route selection policy, you have to reset IPv6 BGP connections to make the new one
take effect. The current IPv6 BGP implementation supports the route-refresh feature that enables
dynamic route refresh without needing to disconnect IPv6 BGP links.
After this feature is enabled on all IPv6 BGP routers, a router that wants to apply a new route selection
policy advertises a route-refresh message to its peers, which then send their routing information to the
router. After receiving the routing information, the router can perform dynamic route update by using
the new policy without tearing down connections.