Dell FCX624-E Laptop User Manual


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1020 PowerConnect B-Series FCX Configuration Guide
53-1002266-01
Optional configuration tasks
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A Layer 3 Switch configured as a route reflector sets the ORIGINATOR_ID attribute to the router
ID of the router that originated the route. Moreover, the route reflector sets the attribute only if
this is the first time the route is being reflected (sent by a route reflector). In previous software
releases, the route reflector set the attribute to the router ID of the route reflector itself. When
a Layer 3 Switch receives a route that already has the ORIGINATOR_ID attribute set, the Layer 3
Switch does not change the value of the attribute.
If a Layer 3 Switch receives a route whose ORIGINATOR_ID attribute has the value of the Layer
3 Switch own router ID, the Layer 3 Switch discards the route and does not advertise it. By
discarding the route, the Layer 3 Switch prevents a routing loop. The Layer 3 Switch did not
discard the route in previous software releases.
The first time a route is reflected by a Layer 3 Switch configured as a route reflector, the route
reflector adds the CLUSTER_LIST attribute to the route. Other route reflectors who receive the
route from an IBGP neighbor add their cluster IDs to the front of the route CLUSTER_LIST. If the
route reflector does not have a cluster ID configured, the Layer 3 Switch adds its router ID to
the front of the CLUSTER_LIST.
If Layer 3 Switch configured as a route reflector receives a route whose CLUSTER_LIST
contains the route reflector own cluster ID, the route reflector discards the route and does not
forward it.
Configuration procedures
To configure a Layer 3 Switch to be a BGP4 route reflector, use either of the following methods.
NOTE
All configuration for route reflection takes place on the route reflectors, not on the clients.
Enter the following commands to configure a Layer 3 Switch as route reflector 1 in Figure 147 on
page 1019. To configure route reflector 2, enter the same commands on the Layer 3 Switch that
will be route reflector 2. The clients require no configuration for route reflection.
PowerConnect(config-bgp-router)#cluster-id 1
PowerConnect(config-bgp-router)#neighbor 10.0.1.0 route-reflector-client
PowerConnect(config-bgp-router)#neighbor 10.0.2.0 route-reflector-client
Syntax: [no] cluster-id <num> | <ip-addr>
The <num> | <ip-addr> parameter specifies the cluster ID and can be a number from 0 through
4294967295 or an IP address. The default is the router ID. You can configure one cluster ID on the
router. All route-reflector clients for the router 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 within the
cluster.
To add an IBGP neighbor to the cluster, enter the following command.
Syntax: neighbor <ip-addr> route-reflector-client
For more information about the neighbor command, refer to “Adding BGP4 neighbors” on
page 993.
By default, the clients of a route reflector are not required to be fully meshed; the routes from a
client are reflected to other clients. However, if the clients are fully meshed, route reflection is not
required between clients.