Summarization with Pre-fix Address

BGP (Border Gateway Protocol) IPv6 summarization with prefix addresses involves aggregating multiple IPv6 prefixes into a more concise form while preserving the specificity of the summarized information. This summarization technique allows BGP routers to represent a range of IPv6 prefixes with a single summary route, optimizing the efficiency of routing tables. Unlike traditional summarization, which might result in the loss of granularity, summarization with prefix addresses maintains individuality for each included IPv6 prefix within the aggregated route. This approach aids in conserving resources and promoting scalability in BGP networks. By incorporating prefix addresses, administrators strike a balance between route aggregation and retaining detailed information, contributing to a more efficient and manageable BGP routing infrastructure for IPv6. Careful configuration is essential to ensure that the aggregated prefixes accurately represent the subnets and avoid unnecessary aggregation that could impact routing precision.

Lab:

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Cisco IOS Software, Linux Software (I86BI_LINUX-ADVENTERPRISEK9-M), Version 15.2(4)M1, DEVELOPMENT TEST SOFTWARE

Task 1: Configure IPv6 BGP Summarization with Pre-fix Address

Step 1: Summarize with BGP routes in router mode with Pre-fix Address

R3: 
router bgp 65000
address-family ipv6
aggregate-address 11::/16
neighbor 44:0:1::4 prefix-list ooo out
exit
exit
ipv6 prefix-list ooo seq 5 deny 11::/16 ge 32
ipv6 prefix-list ooo seq 10 permit ::/0 le 128

here with prefix-list we are denying 11:: network having mask greater or equal to 23 and rest any route it will allow but should be less than 32 because route with 32 mask will be host address.

Step 2: Verify receipt of summary route in other router’s BGP table by following command

R4# show bgp ipv6 unicast
BGP table version is 26, local router ID is 44.0.3.4
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop        Metric    LocPrf    Weight    Path
 *>  11::/16          33:0:1::3         0            	    0       65000 i
 *>  22:0:1::/64      33:0:1::3                             0       65000 i
 *>  22:0:2::/64      33:0:1::3                             0       65000 i
 *>  22:0:3::/64      33:0:1::3                             0       65000 i
 *>  33:0:1::/64      33:0:1::3         0     	            0       65000 i
 *>  33:0:2::/64      33:0:1::3         0     	            0       65000 i
 *>  33:0:3::/64      33:0:1::3         0     	            0       65000 i
 *>  44:0:1::/64      ::                0     	          32768     i
 *>  44:0:2::/64      ::                0       	      32768     i
 *>  44:0:3::/64      ::                0        	      32768     i

Here only summarized route is received using prefix-list.