There are several tools built into Windows Server 2003 to troubleshoot routing problems. The first of these tools is ping. Ping allows you to check the connectivity of a remote host by sending four packets of data to the remote machine. The remote machine responds with a similar packet, and the time for the round trip is reported.The format of the ping command is:
EG, PING 220.127.116.11
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This shows that the remote host 18.104.22.168 is currently unavailable, since there was no ping reply (request timed out).
In this case, the host was available. It’s reply time was less than 10ms, which suggests it is on a local area network.
If there is no route to access the remote network, then you receive a “Destination host unreachable” error – you should check your router or routing tables!
If a remote host fails to respond to ping, then Tracert (“trace route”) allows you to ping every router in the path to the remote host. This will show if a local router is causing the problem, or if it is a remote machine.
The format of the Tracert command is:
Tracert <remote host name or IP>
EG, TRACERT www.google.com
To fix routing problems use the command prompt and the route add command.
For example, one such addition may be written as
route add 22.214.171.124 mask 255.0.0.0 10.0.0.50 metric 5 if 1
Your route is now entered in the routing table. However, this route will disappear next time the computer is rebooted. If you want the route to persist, add a “-p” switch to the route add command (route add –p …).
The route command can be used to control far more than just addition of routes. Some useful extensions are:
- route print – displays the current routing table
- route –f – flushes the routing table, deleting all temporary routes. This is similar to rebooting the computer.
- route delete – deletes a route from the table.
- route /? – displays a help summary, including all possible switches and their syntax.
With RIP routing, the following should be done, checked, or at least borne in mind:
If Rip version 1 is present on the network ensure Rip version 2 routers should be configured to use broadcast.
If silent rip is used then broadcast must also be used as a silent rip host will not receive multicast updates.
Rip v1 does not support variable length subnet masks (VLSM)
Manually update Auto-static routes the first time you establish a connection.
Host and default routes are not propagated by default they must be configured in the advanced tab of the interface.
- Verify that the routing protocol is bound to the correct adapters adapter
- Check for routers between neighbours
- Check router passwords
- Check area Ids