Configure IPv6 BGP Route Summary

Network Requirements

• Set up OSPFv3 neighbors between Device1 and Device3, and configure Device3 to advertise routes 2002:1::/64 and 2002:2::/64 to Device1.
• Set up EBGP neighbors between Device1 and Device2.
• On Device1, aggregate routes 2002:1::/64 and 2002:2::/64 into route 2002::/30 and advertise the aggregated route to Device2.

Network Topology

Figure 13–5 Networking for configuring IPv6 BGP route summary

Configuration Steps

Step 1: Configure the IPv6 global unicast addresses of the interfaces. (Omitted)

Step 2: Configure OSPFv3 so that Device1 can learn the two routes 2002:1:/64 and 2002:2::/64 advertised by Device3.

#Configure Device1.

#Configure Device3.

#View the route table of Device1.

Device1#show ipv6 route 
Codes: C - Connected, L - Local, S - static, R - RIP, B - BGP, i-ISIS 
       U - Per-user Static route 
       O - OSPF, OE-OSPF External, M - Management 
 
L ::1/128 [0/0] 
     via ::, 1w2d:07:35:38, lo0
C 2001:1::/64 [0/0] 
     via ::, 00:01:11, vlan2
L 2001:1::2/128 [0/0] 
     via ::, 00:01:10, lo0
C 2001:2::/64 [0/0] 
     via ::, 00:01:06, vlan3
L 2001:2::2/128 [0/0] 
     via ::, 00:01:04, lo0
O 2002:1::/64 [110/2] 
     via fe80::201:7aff:fe62:bb7e, 00:01:54, vlan2
O  2002:2::/64 [110/2] 
     via fe80::201:7aff:fe62:bb7e, 00:01:54, vlan2 

According to the route table, Device1 has learnt routes 2002:1:1::/64 and 2002:1:2::/64 advertised by Device3.

Step 3: Configure the IPv6 BGP basic functions.

#Configure Device1.

#Configure Device2.

#On Device1, check the IPv6 BGP neighbor status.

Device1#show bgp ipv6 unicast summary  
BGP router identifier 1.1.1.1, local AS number 100 BGP table version is 1 
1 BGP AS-PATH entries 0 BGP community entries 
 
Neighbor     V AS     MsgRcvd MsgSent TblVer InQ OutQ Up/Down      State/PfxRcd 
2001:2::1   4 200    3            3           1         0    0      00:01:16       0 

IPv6 BGP neighbors have been successfully set up between Device1 and Device2.

Step 4: Configure IPv6 BGP route summary.

Two solutions are available to complete the network requirements.

Solution 1: Configure an IPv6 static route that is targeted at null0 to introduce the the static route to BGP.

#Configure Device1.

Check the result.

#View the IPv6 BGP route table of Device1.

Device1#show bgp ipv6 unicast  
BGP table version is 2, local router ID is 1.1.1.1 
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, 
              S Stale 
Origin codes: i - IGP, e - EGP, ? - incomplete 
          Network       Next Hop           Metric  LocPrf Weight Path
[B]*> 2002::/30          ::                0                   32768   i

You can see that the aggregated route 2001::/16 is generated in the IPv6 BGP route table of Device1.

#View the route table of Device2.

Device2#show bgp ipv6 unicast  
BGP table version is 2, local router ID is 2.2.2.2 
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, 
              S Stale 
Origin codes: i - IGP, e - EGP, ? - incomplete 

          Network       Next Hop     Metric  LocPrf Weight Path
[B]*> 2002::/30    2001:2::2    0                   0         100 i

Device2#show ipv6 route 
Codes: C - Connected, L - Local, S - static, R - RIP, B - BGP, i-ISIS 
       U - Per-user Static route 
       O - OSPF, OE-OSPF External, M - Management 
 
L ::1/128 [0/0] 
     via ::, 1w6d:03:14:01, lo0
C 2001:2::/64 [0/0] 
     via ::, 01:20:21, vlan3
L 2001:2::1/128 [0/0] 
     via ::, 01:20:20, lo0
B 2002::/30 [20/0] 
     via 2001:2::2, 00:00:44, vlan3 

Device2 has successfully learnt the aggregated route 2002::/30 that has been advertised by Device1.

Solution 2: First introduce detailed routes into BGP, and then run the aggregate-address command to aggregate the routes.

#Configure Device1.

Check the result.

#Query the IPv6 BGP route table of Device1.

Device1#show bgp ipv6 unicast  
BGP table version is 4, local router ID is 1.1.1.1 
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, 
              S Stale 
Origin codes: i - IGP, e - EGP, ? - incomplete 
          Network         Next Hop           Metric  LocPrf Weight Path
[O]*> 2001:1::/64        ::                 1                  32768   ?
[B]*> 2002::/30           ::                                     32768    i
[O]s> 2002:1::/64        ::                 2                  32768    ?
[O]s> 2002:2::/64        ::                 2                  32768    ? 

The aggregated route 2002::/30 has been generated in the IPv6 BGP route table of Device1.

#View the route table of Device2.

Device2#show bgp ipv6 unicast  
BGP table version is 4, local router ID is 2.2.2.2 
 
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, 
              S Stale 
Origin codes: i - IGP, e - EGP, ? - incomplete 

          Network          Next Hop     Metric  LocPrf Weight Path
[B]*> 2001:1::/64    2001:2::2    1                   0         100 ?
[B]*> 2002::/30       2001:2::2    0                   0         100 i

Device2#show ipv6 route  
Codes: C - Connected, L - Local, S - static, R - RIP, B - BGP, i-ISIS 
       U - Per-user Static route 
       O - OSPF, OE-OSPF External, M - Management 
 
L ::1/128 [0/0] 
     via ::, 1w6d:03:16:42, lo0
B 2001:1::/64 [20/0] 
     via 2001:2::2, 00:00:50, vlan2
C 2001:2::/64 [0/0] 
     via ::, 01:23:01, vlan2
L 2001:2::1/128 [0/0] 
     via ::, 01:23:00, lo0
B 2002::/30 [20/0] 
     via 2001:2::2, 00:00:50, vlan2 

Device2 has successfully learnt the aggregated route 2002::/30 that has been advertised by Device1.

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  When the aggregate-address command is used to aggregate routes, if the extended command summary-only is configured, the device advertises only the aggregated route; otherwise, both common routes and aggregated routes are advertised.

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