Filter
Top Products
Nokia Network Voyager for IPSO 4.0 Reference Guide 409
No special configuration is required on the route reflection clients. From a client perspective, a
route reflector is a normal IBGP peer. Any BGP version 4 speaker should be able to be a
reflector client.
for further details, refer to the route reflection specification document (RFC 2796 as of this
writing).
AS1 has five BGP-speaking routers. With Router B working as a route reflector, there is no need
to have all the routers connected in a full mesh.
Confederations
An alternative to route reflection is BGP confederations. As with route reflectors, you can
partition BGP speakers into clusters where each cluster is typically a topologically close set of
routers. With confederations, this is accomplished by subdividing the autonomous system into
multiple, smaller ASes that communicate among themselves. The internal topology is hidden
from the outside world, which perceives the confederation to be one large AS.
Each distinct sub-AS within a confederation is referred to as a routing domain (RD). Routing
domains are identified by using a routing domain identifier (RDI). The RDI has the same syntax
as an AS number, but as it is not visible outside of the confederation, it does not need to be
globally unique, although it does need to be unique within the confederation. Many
confederations find it convenient to select their RDIs from the reserved AS space (ASes 64512
through 65535 (see RFC 1930)). RDIs are used as the ASes in BGP sessions between peers
within the confederation.
The confederation as a whole, is referred to by a confederation identifier. This identifier is used
as the AS in external BGP sessions. As far as the outside world is concerned, the confederation
ID is the AS number of the single, large AS. For this reason, the confederation ID must be a
globally unique, normally assigned AS number.
Note
Do not nest confederations.
Nokia
Platform A
Nokia
Platform D
Nokia
Platform F
Nokia
Platform G
Nokia
Platform C
Nokia
Platform E
Nokia
Platform B
Non-client
Client
route reflector
Client
Non-client
Cluster
AS676
IBGP
IBGP IBGP
IBGP
EBGP
00328
AS1