n metric=100 If E2 route then metric=100 Figure 11-4. OSPF external route types Redistribution into OSPF defaults to type-2 routes. Which type should you use? That depends on your needs at the time. Generally, in smaller networks (less than, say, 10 routers) E2 routes may be easier to maintain, as they have the same value anywhere in the OSPF autonomous system. But to me, E1 routes function more logically because they increment with each hop, as do most other metrics. To set the route type, add the metric-type keyword to the redistribute command: 3(config-router)# redistribute eigrp 100 metric-type ? 1 Set OSPF External Type 1 metrics 2 Set OSPF External Type 2 metrics The metric type and the metric can be added onto one command line: R3 (config-router)# redistribute eigrp 100 metric-type 2 metric 100 In practice, every time you redistribute into OSPF you should include the keyword subnets: R3 (config-router)# redistribute eigrp 100 metric 100 subnets Chapter 11: Redistribution Without the subnets keyword, OSPF will redistribute only routes that have not been subnetted. In the world of VLSM, where practically all networks are subnets, it is rare that you will not want subnets to be redistributed. If you do not include the subnets keyword on modern versions of IOS, you will be warned about your probable mistake: R3 (config-router)# redistribute eigrp 100 metric 100 % Only classful networks will be redistributed Mutual Redistribution The term mutual redistribution is used when a router redistributes between two rout- ing protocols in both directions instead of just one. Often, we redistribute because there is a device or entity we wish to connect with that doesn't support the routing protocol we have chosen to use. We need to share routes between protocols, but, if you will, the protocols don't speak the same language. Figure 11-5 shows a network in which every subnet needs to be reached by every other subnet. The problem here is that the network on the left is using OSPF, and the network on the right is using EIGR