BGP Lab 20 IPv6 prefix aggregation (CCNP Level)

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


In the last lab, routers in the AS250 injected IPv6 prefixes via redistribution, those routes are subnets of R1 and R2 with /64 prefix length but the policies of  upstream ISPs now have been updated and state that customers have to share the only summary prefixes for their entire autonomous systems, otherwise ISPs will no longer accept prefixes larger than /56 starting next month. 

Lab tasks:

1. Determine if AS250 can advertise /48 prefixes to its upstream eBGP peers. Document necessary changes to the BGP edge routers ER1 and ER2. 

2. Implement prefix aggregation on the router ER1. 

3. Implement prefix aggregation on the router ER2. 

4. Verify on your side that ISP1 and ISP2 potentially received only summarized prefix. 

5. Verify that ISP4 received /48 prefix. 

6. Save running-config. 

Configuration example:

ER1(config)#router bgp 250
ER1(config-router)#address-family ipv6

ER1(config-router-af)#aggregate-address  2001:DB8:250::/48 summary-only
ER1(config-router-af)# end

Perform soft BGP reset:
ER1# clear bgp ipv6 unicast out
ER1# clear bgp ipv6 unicast out
Verify what prefixes local router sends to its ISP:
ER1# show bgp ipv6 unicast neighbor advertised-routes



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