t set 50.0.0.0/24 is subnetted, 1 subnets 50.50.50.0 [170/156160] via 20.20.20.3, 00:00:01, FastEtherneto/1 20.0.0.0/24 is subnetted, 1 subnets 20.20.20.0 is directly connected, FastEtherneto/1 10.0.0.0/24 is subnetted, 1 subnets 10.10.10.0 is directly connected, FastEtherneto/o Another method Here's another method to use, which I like for its elegance: because redistributed routes are external, only allow internal routes to be redistributed. Once a route is redistributed and becomes external, it won't be redistributed again. When you're redistributing OSPF routes into another protocol, this is simple. The keyword match in the redistribute command lets you match on route type: router eigrp 100 redistribute ospf 100 match internal network 20.20.20.0 0.0.0.255 default-metric 100000 100 255 1 1500 no auto-summary Limiting Redistribution When redistributing other protocols, you must resort to route maps: router ospf 100 redistribute eigrp 100 route-map Only-Internal subnets network 10.10.10.0 0.0.0.255 area 0 default-metric 100 route-map Only-Internal permit 10 match route-type internal This solution solves both our problems. As the 50.50.50.0/24 route is an external route by nature of its original redistribution into R3, it will not be redistributed into OSPF. What once required many lines of code and multiple route maps has now been ac- complished with one keyword and a single two-line route map. Simple is good. Here is the final routing table from R2: R2#sho ip route [text removed] Gateway of last resort is not set 50.0.0.0/24 is subnetted, 1 subnets 50.50.50.0 [170/156160] via 20.20.20.3, 00:13:30, FastEtherneto/1 20.0.0.0/24 is subnetted, 1 subnets 20.20.20.0 is directly connected, FastEtherneto/1 10.0.0.0/24 is subnetted, 1 subnets 10.10.10.0 is directly connected, FastEtherneto/o As long as you keep things simple, tagging and filtering redistributed routes is easy. The more complicated the network is, the harder it is to keep all the redistributed networks behaving properly. Additionally, a more complex networ