put the 184.108.40.206/18 summary on R4 f0/0 towards R3. R3 should then have the EIGRP routes
220.127.116.11/18 from R4
18.104.22.168/24 from R5
you will advertise this into OSPF on R3. Don't forget the subnets keyword as this is not a classful summary.
since the OSPF area is only area 0, you don't have an ABR. you have an ASBR in R3.
redistribute the OSPF routes into EIGRP on R3. Then on R3, put the 22.214.171.124/14 summarry only on f0/1 towards R4 and f1/0 towards R5.
you will need to use a route map for both the redistribute commands to filter the original routes back into their original domain.
HI Brian, thanks a lot for your help. I think I got it working now. Well it did resolve it but i hope the syntax was OK. I summarized the 126.96.36.199/18 on R4 as you suggested.
I then used a prefix list and distribute list on R3 just to see if that would work and it did.
R3(config)#ip prefix-list NETWORK-2 deny 188.8.131.52/14
R3(config)#ip prefix-list NETWORK-2 permit 0.0.0.0/0 le 32
THIS got rid of the external route to 184.108.40.206/14 in R1 and R2's routing table and also there won't be any external type
5 LSAs for this network
Alternatively I also used a route map and linked it to a Access-list. Issued on R3
10 deny 220.127.116.11, wildcard bits 0.3.255.255 (1 match)
20 permit any (4 matches)
Then create a route map on R3:
route-map EIGRP>OSPF, permit, sequence 10
ip address (access-lists): 1
ON R3 I issued redistribute eigrp 1 metric 200 metric-type 1 subnets route-map EIGRP>OSPF
This again also seemed to be a viable solution. But would another way of been using tags? Tagging the routes I don't want to be redistributed back into the routing domain they came from? is this better?
In my blog i have done the CBT nugget labs and you will find tagging with route-maps on this page (between OSPF and EIGRP):
Using Tags definitely is a more elegant solution:
Use these route maps in your redistrubute statements. With tagging you won't need to creat ACL in order to filter the prefixes.
route-map EIGRP-into-OSPF permit 10
set tag 20
route-map EIGRP-into-OSPF deny 20
match tag 40
route-map OSPF-into-EIGRP permit 10
set tag 40
route-map OSPF-into-EIGRP deny 20
match tag 20
BTW the thread should said Redistribution Dilemma, your summarization is OK
HI guys, just to clarify. Yes, the DENY statements should be first. I mis-typed that. The other thing, for some reason I was thinking of double redistribution when I suggested this, and this would prevent loops. But here that is not the case.
In these scenario even do you don't filter anything you won't have loops. Now I'm looking into it. Hope to come back soon with a correct explanation.