I'm new to Cisco and I wanted to connect two routers with serial connection. This is how my network looks now:


Maybe I connected them wrong because when I try to ping from PC0 to either PC2 or PC3 I get destination host unreachable on the IP of Router0. So I had an idea that there aren't routes between my FastEthernet and Serial ports and I tried to do that but I'm not sure how or if that's even the right approach.

As I said I'm new to this and my knowledge is not large but please if you have any directions, I'd very much appreciate it! Also I'm sorry if I used any wrong terminology since that's also new to me!

EDIT: I forgot, here is some more info on my devices in question: Router0 has an IP of for Fe0/0 and for Fe0/1 and for Serial 0/1/0 it has an IP of All of them have subnet of

Router1 has an IP of for Fe0/0 and for Fe0/1 and also for Serial 0/1/0 it has an IP of Also subnet mask.

My ultimate goal is to be able to ping from PC0 ( or PC1 ( to PC2 ( or PC3 ( and vice versa!

  • Can the two routers ping each other through the serial connection? – kasperd Mar 30 '14 at 13:11
  • @kasperd Yes they can! both of them return the following: Success rate is 100 percent (5/5), round-trip min/avg/max = 2/9/15 ms – RidableCthulu Mar 30 '14 at 13:13

You might just be missing routing table entries.

  • On Router0 you need to specify a route to using as gateway.
  • On Router1 you need to specify a route to using as gateway.
  • Sorry, It didn't accept my command the first time. Now it works but I still don't understand why use these IP addresses. If it's not a bother could you explain that to me or link somewhere to read about it! Thanks! – RidableCthulu Mar 30 '14 at 13:34
  • Actually I think I got it! Thank you very very much! This community on Serverfault never lets me down :) – RidableCthulu Mar 30 '14 at 13:45
  • If you need to know more about the notation, the Wikipedia article on CIDR may be a good starting point. en.wikipedia.org/wiki/CIDR – kasperd Mar 30 '14 at 13:57
  • I did understand that part (I even printed out a nice sheet with all of it for now until I hopefully memorize most of it) but I was confused why did you use this specific IPs but I think I understand! – RidableCthulu Mar 30 '14 at 14:48

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.