cbt ccna 200 301

cbt ccna 200 301.Router ID (RID) must be unique No | YesK values must match Yes N/AMust be in the same area N/A YesHaving a dual EIGRPRID does not prevent a router from becoming a neighbor, but it can cause problems when external EIGRP routes are added to the routing. Unlike the remaining neighbor necessities listed in Table H-2, the first three neighbor necessities have essentially little to do with the routing protocol itself. Two routers connected to the same physical network must be able to send packets to each other over that physical network. The router interfaces must be in the up/up state for this to happen, and they must be on the same subnet. In addition, routers do not have to use ALC to filter routing protocol traffic. For example, OSPF sends many messages to multicast IP addresses 224.0.0.5 and 224.0.0.6, while EIGRP uses 224.0.0.10. In the incoming ACL on the router interface, the ACL command (such as access-list101 denyip any host 224.0.0.10) filters incoming EIGRP packets. Alternatively, an ACL command like access-list 102 deny ospf any host might screen all OSPF traffic. Therefore, always be careful with ACLs, especially when all routing protocols appear to be OK. In particular, before checking other details about why two routers cannot be neighbors, first make sure that the two routers can ping through to each other in the local subnet. If pinging fails, investigate all Layer 1, 2, and 3 issues that might prevent pinging from working properly (e.g., the interface is not in the up/up state), which are covered in Chapters 4 and 5 of this book and in many chapters of ICND1. Since the details of the two routing protocols do not differ much from each other, this subsection first introduces EIGRP-related items . This section will then analyze OSPF.Tip: This section assumes that the routing protocol has been enabled on each required interface, as described in the "Interfaces Enabled with the Routing Protocol" section earlier in this chapter.EIGRP Neighbor Verification Check that any two EIGRP routers connected to the same data link can at least be considered neighbors if their interfaces are EIGRP-enabled and are not passive interfaces. Here it is only necessary to look at the output of the showipeigrpneighbors command to quickly and definitively know which potential neighbors have passed all EIGRP neighbor requisites. This command lists only the neighboring routers that have passed all neighbor condition verification checks. Example H-7 gives an example of the showipeigrpneighbors command, where the four routers are also a continuation of the configuration in Figure 11-3.configuration. In this example, all routers have been configured correctly, so each router has established a neighbor relationship with the other three routers on the same LAN subnet.Example 11-7 After All Problems Are Solved R1's showip eigrp neighbors CommandEIGRP-IPv4 Neighbors for AS (99)H Address Interface Hold Uptime SRTTRTO Q Seq