Service Manual

With route reection congured properly, IBGP routers are not fully meshed within a cluster but all receive routing information.
Congure clusters of routers where one router is a concentration router and the others are clients who receive their updates from
the concentration router.
To congure a route reector, use the following commands.
• Assign an ID to a router reector cluster.
CONFIG-ROUTER-BGP mode
bgp cluster-id cluster-id
You can have multiple clusters in an AS.
• Congure the local router as a route reector and the neighbor or peer group identied is the route reector client.
CONFIG-ROUTER-BGP mode
neighbor {ip-address | peer-group-name} route-reflector-client
When you enable a route reector, Dell Networking OS automatically enables route reection to all clients. To disable route reection
between all clients in this reector, use the no bgp client-to-client reflection command in CONFIGURATION
ROUTER BGP mode. All clients must be fully meshed before you disable route reection.
To view a route reector conguration, use the show config command in CONFIGURATION ROUTER BGP mode or the show
running-config bgp
in EXEC Privilege mode.
Aggregating Routes
Dell Networking OS provides multiple ways to aggregate routes in the BGP routing table. At least one specic route of the aggregate
must be in the routing table for the congured aggregate to become active.
To aggregate routes, use the following command.
AS_SET includes AS_PATH and community information from the routes included in the aggregated route.
• Assign the IP address and mask of the prex to be aggregated.
CONFIG-ROUTER-BGP mode
aggregate-address ip-address mask [advertise-map map-name] [as-set] [attribute-map map-
name] [summary-only] [suppress-map map-name]
Example of Viewing Aggregated Routes
In the show ip bgp command, aggregates contain an ‘a’ in the rst column (shown in bold) and routes suppressed by the
aggregate contain an ‘s’ in the rst column.
Dell#show ip bgp
BGP table version is 0, local router ID is 10.101.15.13
Status codes: s suppressed, d damped, h history, * valid, > best
Path source: I - internal, a - aggregate, c - confed-external, r - redistributed, n -
network
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 7.0.0.0/29 10.114.8.33 0 0 18508 ?
*> 7.0.0.0/30 10.114.8.33 0 0 18508 ?
*
>a 9.0.0.0/8 192.0.0.0 32768 18508 701 {7018 2686 3786} ?
*> 9.2.0.0/16 10.114.8.33 0 18508 701 i
*> 9.141.128.0/24 10.114.8.33 0 18508 701 7018 2686 ?
Dell#
Conguring BGP Confederations
Another way to organize routers within an AS and reduce the mesh for IBGP peers is to congure BGP confederations.
As with route reectors, BGP confederations are recommended only for IBGP peering involving many IBGP peering sessions per
router. Basically, when you congure BGP confederations, you break the AS into smaller sub-AS, and to those outside your network,
Border Gateway Protocol IPv4 (BGPv4)
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