â– Example
host1:pe1(config-route-map)#match mpls-label
â– Use the no version to remove the configuration.
â– See match mpls-label.
neighbor send-label
â– Use to configure a BGP peer to distribute an MPLS label with the advertisements
for its IPv4 and IPv6 routes.
â– This command enables BGP to dynamically negotiate SAFI 1 and SAFI 4 with
this neighbor.
â– Example
host1(config-router-af)#neighbor 10.19.1.2 send-label
â– Use the no version to halt distribution of the MPLS label with route
advertisements.
â– See neighbor send-label.
set mpls-label
â– Use to configure BGP to advertise prefixes that match the route map as labeled
prefixes.
â– Example
host1:pe1(config-route-map)#set mpls-label
â– Use the no version to remove the configuration.
â– See set mpls-label.
BGP Next-Hop-Self
When a BGP router reports itself as the next hop, whether because of an explicit
neighbor next-hop-self configuration or implicitly as a result of participating in an
EBGP session, BGP allocates a new in label and adds an entry to the MPLS forwarding
table, creating a label-to-next-hop mapping.
When a BGP router does not report itself as the next hop, whether because of an
explicit neighbor next-hop-unchanged configuration or implicitly as a result of a
participating in an IBGP session, BGP does not allocate a new in label. Instead, if the
route is advertised as a labeled route, BGP uses the existing out label. This feature is
used mainly on route reflectors.
The determination to allocate an in label is made only after the outbound route map
has been processed. Therefore, the in label allocation and the creation of the
label-to-next-hop mapping are performed after the need is apparent, conserving the
number of in labels allocated.
Configuring BGP VPN Services â– 459
Chapter 5: Configuring BGP-MPLS Applications
To Next Page
Loading...
Need help?
General
