 when redistributing them. The route tags are nothing more than numbers within the range of 0-4,294,967,295 (unfortunately, the tags can- not be alphanumeric). Route tags do not affect the protocol's actions; the tag is simply a field to which you can assign a value to use elsewhere. To set a route tag when redistributing into OSPF, add the tag tag# keyword to the redistribute command: R2(config-router)#redistribute eigrp 100 metric 10 subnets tag 2 This command will redistribute routes from EIGRP 100 into OSPF. The OSPF metric will be 10, and the tag will be 2. To see the tags in OSPF routes, use the show ip ospf database command. Redistributed routes will be external routes. The last column will be the tags for these routes: R2#sho ip ospf dat OSPF Router with ID (10.10.10.2) (Process ID 100) Router Link States (Area 0) Link ID ADV Router Checksum Link count 10.10.10.2 10.10.10.2 0x80000002 0x00F5BA 20.20.20.1 20.20.20.1 0x80000002 0x009DD9 1 Net Link States (Area 0) Link ID ADV Router Checksum 10.10.10.1 20.20.20.1 0x80000001 0x00B5CA Type-5 AS External Link States Limiting Redistribution Link ID ADV Router Checksum Tag 20.20.20.0 10.10.10.2 0x80000001 0x00D774 2 20.20.20.0 20.20.20.1 0x80000001 0x002DF9 0 50.50.50.0 10.10.10.2 0x80000001 0x009B56 2 To set a route tag in EIGRP, you need to use route maps. Luckily for those of you who have a route-map phobia, the method I'll show you is one of the simplest ways to deploy them. Route maps are cool! There, I said it. Route maps are quite powerful, and if you have a fear of them, I suggest you spend some time playing around with them. The fear is usually based in confusion between route maps and access lists and how they interact. It will be well worth your time to learn more about route maps. They can get you out of a technical corner (such as a redistribution loop) when no other option exists. See Chapter 14 for more information. To apply a tag to a redistributed route in EIGRP, you must first create a route map, and then call it in a redistribute command line. 