Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I need server A to be able to reach server C (a mail server). server B can already reach server C and server A can reach server B. Is there a few simple steps I can take to add a static route to server A to solve this?

share|improve this question
Need more info. Are these machines on the same network? What do you mean by 'reach eachother' and what OS is each machine running? – cop1152 Aug 19 '09 at 17:48

No, at least in IP space.

If they aren't on the same subnet (xxx.yyy.zzz.1 and xxx.yyy.zzz.2) the two computers will require a router to connect them. If they are on the same subnet then a switch is all that is required.

Given the simplicity of you question means we're guessing blind, I'd first recommend that you check to see if A and C both have a "default gateway" that matches an IP of a local router for each of their subnets. And I'd check for firewalling (both software and hardware) at the same time.

share|improve this answer


  • A is
  • C is
  • B is both and
  • B has an OS on it that permits routing, or forwarding:

on A:

route add -host

on B:

  • make sure forwarding is enabled; this is done in different ways by different OSs

on C:

route add -host

Now A should be able to interact with C, and vice versa.

(Warning: route syntax above is from Solaris, because that's what I have historically spent most of my time with; linux and windows routing is done slightly differently. Also, making all these changes permanent across reboots is left as an exercise to the reader.)

share|improve this answer
Syntax for Windows is: route add x.x.x.x mask y.y.y.y (where x = destination, y = ip of 2nd network card) – Mark Henderson Aug 20 '09 at 3:12
Will Windows really act as a router without extra networking software being installed? Is there a Role that allows this? – Mark Jun 29 '11 at 20:27
@Mark -- usually you have to turn it on for most OSs (although by default Solaris will enable routing if it boots with two interfaces with separate subnets defined). – David Mackintosh Jul 5 '11 at 1:58

As others have said, more information is needed.

If Server A is Windows you can try:

route ADD ServerCIPAddress MASK NetMaskOfABSubNet ServerBIPAddress

however it's likely that the three servers are on different subnets, which means this won't work...

In that case you will need to do something about the router / switch configuration.

share|improve this answer
ok, thank you. They are on different subnets. I'll see if I can find someone to help w/the router. – Hetano Aug 20 '09 at 15:20

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.