BGP Lab 21 Leaking IPv6 prefix (CCNP Level)

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Image requirements:
 Cisco IOSv (vios-adventerprisek9-m.vmdk.SPA.156-2.T)


In the previous lab, you were aggregating /64 prefixes of AS250 into one /48 prefix, but there is a new requirement came up that subnet of R1's loopback1 interface 2001:db8:250:A103::/64 has to be advertised alongside summary prefix by only edge router ER1.

Lab Tasks: 

1. Verify that ISP4 is only receiving /48 prefix of AS250. 

2. Configure the prefix-list that identifies the R1's last subnet.

3. Configure the route-map and match the prefix-list from step 2. 

4. Modify the aggregate-address command to include the route-map. 

5. Verify that upstream ISPs received more specific /64 prefix alongside /48. 

6. Save running-config. 

Configuration example:

ER1(config)#ipv6 prefix-list R1_SUBNET103 permit 2001:DB8:250:A103::/64
ER1(config)#route-map LEAK_SPECIFIC deny  10
ER1(config-route-map)#match  ipv6  address  prefix-list R1_SUBNET103

ER1(config)#route-map LEAK_SPECIFIC permit 20
ER1(config)#router bgp 250
ER1(config-router)#address-family ipv6
ER1(config-router-af)#aggregate-address 2001:DB8:250::/48 summary-only suppress-map LEAK_SPECIFIC

Verify Leaked route:
ER1# show bgp ipv6 unicast neighbor advertised-routes




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