Support for rfc 4456, Configuration procedures – Brocade Multi-Service IronWare Routing Configuration Guide (Supporting R05.6.00) User Manual
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Multi-Service IronWare Routing Configuration Guide
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Configuring route reflection parameters
Support for RFC 4456
Route reflection is based on RFC 4456. This updated RFC helps eliminate routing loops that are
possible in some implementations of the older specification, RFC 1966. These instances include:
•
The device adds the route reflection attributes only if it is a route reflector, and only when
advertising IBGP route information to other IBGP neighbors. The attributes are not used when
communicating with EBGP neighbors.
•
A device configured as a route reflector sets the ORIGINATOR_ID attribute to the device ID of
the device that originated the route. The route reflector sets this attribute only if this is the first
time the route is being reflected (sent by a route reflector).
•
If a device receives a route with an ORIGINATOR_ID attribute value that is the same as the ID of
the device, the device discards the route and does not advertise it. By discarding the route, the
device prevents a routing loop.
•
The first time a route is reflected by a device configured as a route reflector, the route reflector
adds the CLUSTER_LIST attribute to the route. Other route reflectors that receive the route
from an IBGP neighbor add their cluster IDs to the front of the routes CLUSTER_LIST. If the
route reflector does not have a cluster ID configured, the device adds its device ID to the front
of the CLUSTER_LIST.
•
If a device configured as a route reflector receives a route with a CLUSTER_LIST that contains
the cluster ID of the route reflector, the route reflector discards the route.
Configuration procedures
NOTE
All configuration for route reflection takes place on the route reflectors, not on the clients.
Enter the following commands to configure a device as route reflector 1 in
on page 93. To configure route reflector 2, enter the same commands on the device
that will be route reflector 2. The clients require no configuration for route reflection.
Brocade(config-bgp)# cluster-id 1
Syntax: [no] cluster-id num | ip-addr
The num | ip-addr parameters specify the cluster ID and can be a number from 1 – 4294967295,
or an IP address. The default is the device ID. You can configure one cluster ID on the device. All
route-reflector clients for the device are members of the cluster.
NOTE
If the cluster contains more than one route reflector, you need to configure the same cluster ID on
all the route reflectors in the cluster. The cluster ID helps route reflectors avoid loops in the cluster.
To add an IBGP neighbor to the cluster, enter the following command:
Brocade(config-bgp)# neighbor 10.0.1.0 route-reflector-client
Syntax: [no] neighbor ip-addr route-reflector-client
For more information about the neighbor command, refer to