Troubleshooting WAN Connections can be a real pain with multiple ISP’s in-between here and there. This guide should help a little.

Say for example we have a T1 or DS1, usually it’s composed somewhat like this

Branch Office Network –> Cisco Router –> T1–>Cisco Router –> Remote Office Network

as you can see there are at least four points 2/4 of them are out of your control generally, and there’s in most cases there is a few switches in-between unless the T1 is going to somewhere in the same town.

there’s two tools that you can use to determine where the problem is at.

1) Ping

ping 192.168.2.1 (or whatever the ip is of your router on the other side.) Use the IP, not the DNS name for the best results.

ping the router on the other side, and see if you get a response. If you do not get a response, it’s time to move on to the next tool

2) tracert

type tracert, and the name/ip address, in this example we used Google.

as you can see the first thing in this example is the computer is routed to the default gateway (192.168.195.254)

after that you can see there is another hop, but for whatever reason that is not responding, or ping is turned off.

there’s a few more hops in there, more than likely switches and routers from ISP company.

let’s do one that’s un-successful, keep in mind that the max number of hops you can have is 30, and is usually much less.

as you can see, by the time out, that’s more than likely where the issue is, in this case, somewhere after it hits Milwaukee, WI’s Road Runner Service. Based on the fact that the last two are DNS servers we can come to the conclusion that either the final router at the other end, or a link between Time Warner an the other end is down.

At this point contact your person on the other end of the connection and let them know what’s going on, usually explanations start happening at this point. If nothing from your end, then it has to be the ISP, at that point i would open a support ticket with your T1/DS1 Provider.

That’s it! hopefully this blog was helpful in determining WAN connectivity problems.