Aggregating Routes; Configuring Bgp Confederations - Dell S6100 Configuration Manual

To view a route reflector configuration, 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 specific route of the aggregate must
be in the routing table for the configured 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 prefix 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 first column (shown in bold) and routes suppressed by the aggregate
contain an 's' in the first 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
*> 7.0.0.0/29 10.114.8.33
*> 7.0.0.0/30 10.114.8.33
*>a 9.0.0.0/8 192.0.0.0
*> 9.2.0.0/16 10.114.8.33
*> 9.141.128.0/24 10.114.8.33
Dell#

Configuring BGP Confederations

Another way to organize routers within an AS and reduce the mesh for IBGP peers is to configure BGP confederations.
As with route reflectors, BGP confederations are recommended only for IBGP peering involving many IBGP peering sessions per router.
Basically, when you configure BGP confederations, you break the AS into smaller sub-AS, and to those outside your network, the
confederations appear as one AS. Within the confederation sub-AS, the IBGP neighbors are fully meshed and the MED, NEXT_HOP, and
LOCAL_PREF attributes are maintained between confederations.
To configure BGP confederations, use the following commands.
• Specifies the confederation ID.
CONFIG-ROUTER-BGP mode
bgp confederation identifier as-number
• as-number: from 0 to 65535 (2 Byte) or from 1 to 4294967295 (4 Byte).
• Specifies which confederation sub-AS are peers.
CONFIG-ROUTER-BGP mode
bgp confederation peers as-number [... as-number]
• as-number: from 0 to 65535 (2 Byte) or from 1 to 4294967295 (4 Byte).
All Confederation routers must be either 4 Byte or 2 Byte. You cannot have a mix of router ASN support.
Metric LocPrf Weight Path
0 0 18508 ?
0 0 18508 ?
32768 18508 701 {7018 2686 3786} ?
0 18508 701 i
0 18508 701 7018 2686 ?
Border Gateway Protocol IPv4 (BGPv4) 205