Question : MTU Setting for Remote Desktop / SQL Server

We have just connected two networks together using ethernet interfaces (two cisco 1841 routers).I can ping accross, access http/https, pop, smtp, etc but can not access sql server or remote desktop (windows).

All ethernet interfaces are at the default mtu 1500.

I can not figure out why these services can not go through. Do I need to increase the mtu or decrease it?

This is very urgent as the one side of the network can not access sql server.

Answer : MTU Setting for Remote Desktop / SQL Server

It probably is not the MTU, but if you wish to adjust you will want to decrease it on the connecting PC and it's nearest  router. Try 1300. If that works then gradually increase it.

A few other things you may want to check:
-Is the Windows or any other software firewall disabled, at least for test purposes, on the computer to which you are connecting
As for Remote desktop;
-try connecting by IP rather than name
-make sure it is "listening" for your connection. To do so at a command line of the unit to which you are trying to connect:
  netstat  -an  |find  "3389"
You should get the following result:
TCP   0.0.0.0:3389    0.0.0.0:0    listening
If not go to Start  | Run | services.msc and see if Terminal Services is started and set to automatic
-the connecting user must be a member of the remote users group, of the computer to which you are connecting, or a group which is a member. I assume this is not the problem as you would get an error to that effect