From: Roman Rodichev (rodic000@xxxxxxxxxxx)
Date: Sat Jun 02 2001 - 22:01:49 GMT-3
This is a great scenario! Luke, thanks a lot for this one!
You can't achieve you goal using EIGRP and/or OSPF summarization. You are
trying to go from /22 to /24. If you try creating "ip summary-address eigrp"
on R5, R3 will lose connectivity to R5's IP address. Actually, if you think
about it, you won't be able to ping even the local interface! :) Hah! R3
should have two routes:
C 172.16.24.0/22 directly connected
D 172.16.24.0/24 via 172.16.24.5
If you try to ping local interface (172.16.24.3), you should not be able to.
I'm pretty sure about it. It will loop through the routing table. It will
try to find 172.16.24.3 and will match a more specific EIGRP route pointing
172.16.24.5. So it will try to find 172.16.24.5 and will match the same
route again and then fail, resulting in unsuccessful pings. Heh heh. That's
why you never want to put summary-address statements on EIGRP interfaces
specifing a more specific subnet than then the network of the interface!
Ok, you could also create OSPF summary-address on R3. But you will have the
same problem. OSPF will create a route to NULL0, that will block all of the
traffic destined for 172.16.24.0/22.
The only way out is creating 4 static routes on R3 and redistributing them
into OSPF.
ip route 172.16.24.0 255.255.255.0 eth0
ip route 172.16.25.0 255.255.255.0 eth0
ip route 172.16.26.0 255.255.255.0 eth0
ip route 172.16.27.0 255.255.255.0 eth0
Roman
>From: "Luke Mendoza" <luke.mendoza@home.com>
>Reply-To: "Luke Mendoza" <luke.mendoza@home.com>
>To: "Ccie \(E-mail\)" <ccielab@groupstudy.com>
>Subject: EIGRP >>> OSPF >>> RIP
>Date: Sat, 2 Jun 2001 15:40:41 -0700
>
>Okay here is the quick run down of the topology:
>
>
>
>R5 >>>>> R3 >>>>>> R1 >>>>>> R4
>
>R5 and R3 are running EIGRP
>R3 and R1 are running OSPF
>R1 and R4 are running RIP
>
>Between R5 and R3 the network is 172.16.24.5 and 172.16.24.3 with a mask of
>255.255.252.0
>
>Between R3 and R1 I have 172.16.123.3 and 172.16.123.1 with a mask of
>255.255.255.0
>
>Between R1 and R4 I have 172.16.14.1 and 172.16.14.4 with a mask of
>255.255.255.0
>
>
>Ok.. so I redistribute EIGRP to OSPF and vice versa
>then I redistributed OSPF to RIP and vice versa..
>
>
>Network 172.16.24.0 doesn't show up on R4 because of the mask /22
>
>How and where should I summarize 172.16.24.0 /22? I can't do a summary of
>172.16.0.0 because I have other networks floating around in the classful
>172.16.0.0 network. How can I unsummarize 172.16.24.0 /22 to 172.16.24.0
>/24????
>**Please read:http://www.groupstudy.com/list/posting.html
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