Configuring The As_Path Attribute; Tuning And Optimizing Ipv6 Bgp Networks - HPE FlexNetwork HSR6800 Configuration Manual

Configuring the AS_PATH attribute

Step
Enter system view.
1.
Enter BGP view.
2.
Enter IPv6 address family
3.
view.
Allow the local AS number to
4.
appear in AS_PATH of
routes from a peer or peer
group and specify the repeat
times.
Specify a fake AS number
5.
for an IPv6 peer or peer
group.
Disable IPv6 BGP from
6.
considering the AS_PATH
during best route selection.
Configure to carry only the
7.
public AS number in updates
sent to a peer or peer group.
Substitute the local AS
8.
number for the AS number of
an IPv6 peer or peer group
identified in the AS_PATH
attribute.

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.
•
IPv6 BGP timers
After establishing an IPv6 BGP connection, two routers send keepalive messages periodically
to each other to maintain 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 message is sent,
nor holdtime is checked.
•
IPv6 BGP connection soft reset
After modifying a route selection policy, 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.
If a peer not supporting route-refresh exists in the network, configure the peer keep-all-routes
command to save all routes from the peer. When the routing policy is changed, the system will
update the IPv6 BGP routing table and apply the new policy.
Command
system-view
bgp as-number
ipv6-family
peer { ipv6-group-name |
ipv6-address } allow-as-loop
[ number ]
peer { ipv6-group-name |
ipv6-address } fake-as
as-number
bestroute as-path-neglect
peer { ipv6-group-name |
ipv6-address } public-as-only
peer { ipv6-group-name |
ipv6-address } substitute-as
362
Remarks
N/A
N/A
N/A
Optional.
Not allowed by default.
Optional.
Not specified by default.
Optional.
Enabled by default.
Optional.
By default, IPv6 BGP updates
carry private AS number.
Optional.
Not substituted by default.