You are quite welcome. I am glad that our responses have helped you understand the problem and led you to a solution. These communities are excellent places to ask questions and to learn about networking. And one advantage is frequently to have more than one person making suggestions about your issue. I hope to see you continue to be active in the community.   HTH   Rick ... View more

I do not know what kind of assignment you have. But saying that there need to be 3 addresses in each network does not make sense when you are talking about a point to point serial interface connecting 2 routers.    Rather than giving you a series of step by step changes to make I am going to try to explain what is going on and what needs to be done in a way that I hope will enable you to understand what is involved and to create your own config changes. Starting with a basic principle of networking that when two devices are connected by a network segment that both devices should have IP addresses in the same subnet. Being locally connected will allow them to communicate directly and easily. I hope that you understand that communicating to a resource that is local is much more simple that communicating with something that is remote.   Your network has 3 point to point serial links. So the first step is that you should choose 3 IP subnets to use on these serial links. Since a point to point serial can have only 2 connected devices you only need 2 usable IP addresses in each subnet and so a /30 subnet is appropriate. The subnets that you previously used might be appropriate choices or you might choose other subnets if you want a fresh start. Once you have chosen 3 subnets I suggest that on your diagram that you label each point to point serial with its subnet.   Once you have assigned subnets to each link the next step is to assign IP addresses to interfaces. Each of your subnets has 2 usable addresses. Assign 1 address to the interface of one router and assign the other address to the interface of the other router. I suggest that on your diagram that you label each of the router serial interfaces with its address.   Once you have figured out which address to assign to each interface then you are ready to make configuration changes to each of your routers to implement what you have labeled in your diagram. This should result in each router being able to ping each of its neighbors. If that is not the case then please post your updated diagram and the current configs of the router interfaces. If there is any part of this which is not clear then please ask questions.   HTH   Rick  ... View more

Thank you for posting more information with configs and with a diagram. It confirms what I have been saying about the problem.   Do you understand what I have been saying about mismatched subnets on the serial interfaces? Do you need help in figuring out how to fix it?   As an example of the issue R1 connects to R2 using Serial0/0/1 on both routers. R1 has configured its subnet to be 192.168.72.60. But R2 has configured its subnet to be 192.168.72.56. R1 has no idea of where 192.168.72.58 (the IP of R2) is or how to get there. And similar issue on R2 which has no idea where 192.168.72.62 is or how to get there. That is why ping does not work and probably why RIP does not work.   HTH   Rick ... View more

I suggest the first thing you should do is to fix the mismatch in subnets between your serial interfaces. The second thing I would suggest is to test on each of your 3 routers whether it is able to ping the IP address of its neighbor on the serial interfaces. If you fix the problem with addressing and if each router is able to ping each of its neighbor serial interface addresses then we will see where we are with routing. But those two things need to be done first.   HTH   Rick ... View more

I have read through the thread again and realize that I was sort of incorrect in my statement about subnets on connected interfaces. But my fundamental point is still correct.  The diagram does make clear that the routers are connected on their serial 0/0/1 interfaces. Here is the config from R1 interface Serial0/0/1 ip address 192.168.72.62 255.255.255.252 and it is clearly in subnet 192.168.72.60 And here is the config from R2 interface Serial0/0/1 ip address 192.168.72.58 255.255.255.252 and it is clearly in subnet 192.168.72.56   I believe that there is additional insight into the problem if we look at the post that has the output of show ip route. It is clearly from R1. As we look at that output we would notice that it has only local and connected entries. It is not receiving any routing updates from its neighbor. Clearly the reason that ping fails is that there is no route to the destination subnet in the routing table. I suspect that this is due to the mismatch of addressing on the serial interfaces used for this connection.   HTH   Rick   ... View more

Yes auto summarization would come into play if there were different major networks involved. But since all subnets are in the same class C 192.168.72 then summarization does not come into play.   One thing that I notice is that the subnet of the serial interface on the first router does not match up with either of the subnets on serial interfaces on the second router. It is not clear what connects to what. But you need to have both ends of that connection in the same subnet.   HTH   Rick ... View more

Good morning. I am glad that my suggestion was helpful. After we got some clarification about what you really wanted to achieve the solution was fairly simple. That config looks appropriate and should work fine. Thank you for marking this question as solved. This will make it easier for other participants in the community to identify discussions which have helpful information. These communities are excellent places to ask questions and to learn about networking. I hope to see you continue to be active in the community.   I believe it should support .1X but do not have much experience with that model of router and so my answer is certainly not authoritative.   HTH   Rick ... View more