Good morning at all, I m new in the forum and I will thank everybody can answer me at a question on route summarization.
I don’t understand the difference when to apply the ip summary-address on interface or when to apply at protocol level. If I apply it at interface, after disable auto-summary, (like the example of
Todd Lemmle book at section 7.10)
Core#config t
Core(config)#router eigrp 10
Core(config-router)#network 192.168.10.0
Core(config-router)#network 10.0.0.0
Core(config-router)#no auto-summary
Core(config-router)#interface ethernet 0
Core(config-if)#ip summary-address eigrp 10 192.168.10.64 255.255.255.224
(In the book it’s wrote this: The summary route we will advertise to the backbone network is placed on the interface connected to the backbone, not under the routing process. This summary route tells EIGRP to find all networks in the 192.168.10.64 network with a block size of 32 and advertise them as one route out interface E0. This means, basically, that any packet with a destination IP address of 192.168.10.64 through 192.168.10.95 will be forwarded via this summary route).
If I try on Cisco Packet Tracer or in the GNS3 this examples and if I have on the Core router other 2 network card with other 2 router, in all router attached at the Core I find all the route summarized of all router. I assumed that I could find only in the Router linked at ETH0.
Another question: If I add another router in cascade on link of the network 192.168.10.96 and another in cascade with the network 192.168.10.128
(R0 eth0<---R_CORE--> 192.168.10.64 -->R1-->192.168.10.96-->R2--->192.168.10.128), too this 2 network (.96 --.128) are advertised in all router attached at core, not only at router R0 linked at eth0’s CORE.
Can somebody explain or clarify me why that route are advertised in all router and not only in the router R0 and and why are advertised also .96 and .128? Seem like summary address at protocol level.
Thank you in advance.
