WB1 7.33 BGP Aggregation - AS-Set

7.33 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.

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

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Rack1R1#show ip bgp
BGP table version is 270, 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
* i10.0.0.0/22      155.1.45.5               0    100      0 200 i
*>                  155.1.13.3               0             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        54.1.1.254               0    100      0 54 i
s>i                 204.12.1.254             0    100      0 54 i
s i115.0.0.0        54.1.1.254               0    100      0 54 i
s>i                 204.12.1.254             0    100      0 54 i
s i116.0.0.0        54.1.1.254               0    100      0 54 i
   Network          Next Hop            Metric LocPrf Weight Path
s>i                 204.12.1.254             0    100      0 54 i
s i117.0.0.0        54.1.1.254               0    100      0 54 i
s>i                 204.12.1.254             0    100      0 54 i
s i118.0.0.0        54.1.1.254               0    100      0 54 i
s>i                 204.12.1.254             0    100      0 54 i
s i119.0.0.0        54.1.1.254               0    100      0 54 i
s>i                 204.12.1.254             0    100      0 54 i
* i155.1.0.0        155.1.146.6              0    100      0 i
*>i                 155.1.146.4              0    100      0 i
* i192.10.1.0       155.1.45.5               0    100      0 200 i
*>                  155.1.13.3                             0 200 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#
Rack1R1#show ip bgp 112.0.0.0/5
BGP routing table entry for 112.0.0.0/5, version 262
Paths: (1 available, best #1, table Default-IP-Routing-Table)
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
Rack1R1#