LAB: BGP - Aggregation AS-Set

- Configure R1 to aggregate the subnets 112.0.0.0/24-119.0.0.0/24 into one prefix using the optimal prefix length.
- Ensure that the new summary prefix is not accepted by AS 54 peers.
- Do not use any filtering technique to accomplish this

configuration:


R1:
router bgp 100
aggregate-address 112.0.0.0 248.0.0.0 summary-only as-set


verification:

Rack1R1#show ip bgp
BGP table version is 55, local router ID is 150.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 10.0.0.0/22      155.1.13.3               0             0 200 i
* i                 155.1.45.5               0    100      0 200 i
*>i10.0.1.0/24      155.1.67.7               0    100      0 300 200 i
*>i28.119.16.0/24   54.1.1.254               0    100      0 54 i
* i                 204.12.1.254             0    100      0 54 i
*>i28.119.17.0/24   54.1.1.254               0    100      0 54 i
* i                 204.12.1.254             0    100      0 54 i
s i112.0.0.0        204.12.1.254             0    100      0 54 50 60 i
s>i                 54.1.1.254               0    100      0 54 50 60 i
*> 112.0.0.0/5      0.0.0.0                       100  32768 {54,50,60} i
s i113.0.0.0        204.12.1.254             0    100      0 54 50 60 i
s>i                 54.1.1.254               0    100      0 54 50 60 i
s i114.0.0.0        204.12.1.254             0    100      0 54 i
s>i                 54.1.1.254               0    100      0 54 i
s i115.0.0.0        204.12.1.254             0    100      0 54 i
s>i                 54.1.1.254               0    100      0 54 i
s i116.0.0.0        204.12.1.254             0    100      0 54 i
   Network          Next Hop            Metric LocPrf Weight Path
s>i                 54.1.1.254               0    100      0 54 i
s i117.0.0.0        204.12.1.254             0    100      0 54 i
s>i                 54.1.1.254               0    100      0 54 i
s i118.0.0.0        204.12.1.254             0    100      0 54 i
s>i                 54.1.1.254               0    100      0 54 i
s i119.0.0.0        204.12.1.254             0    100      0 54 i
s>i                 54.1.1.254               0    100      0 54 i
* i155.1.0.0        155.1.146.4              0    100      0 i
*>i                 155.1.146.6              0    100      0 i
* i205.90.31.0      155.1.45.5               0    100      0 200 254 ?
*>                  155.1.13.3                             0 200 254 ?
* i220.20.3.0       155.1.45.5               0    100      0 200 254 ?
*>                  155.1.13.3                             0 200 254 ?
* i222.22.2.0       155.1.45.5               0    100      0 200 254 ?
*>                  155.1.13.3                             0 200 254 ?

Rack1R1#show ip bgp 112.0.0.0 248.0.0.0
BGP routing table entry for 112.0.0.0/5, version 47
Paths: (1 available, best #1, table Default-IP-Routing-Table)
Multipath: iBGP
Flag: 0x820
  Advertised to update-groups:
     1          2        
  {54,50,60}, (aggregated by 100 150.1.1.1)
    0.0.0.0 from 0.0.0.0 (150.1.1.1)
      Origin IGP, localpref 100, weight 32768, valid, aggregated, local, best