[wellylug] Routing problem

[Gawain Lynch]

On Thu, 2006-01-19 at 12:06 +1300, Ian Beardslee wrote:
> Hi all,
> 
> I have a wee routing problem.  At least I think it is a routing problem, 
> it could be a 'stoopid Ian' problem, but I am going with the routing 
> problem for now.

Hmmm, that sounds very similar to the plethora of 'stoopid Gawain'
problems that I have seen over the years  ;-)

> I have a network.  In that network is a machine (let's call it 'ubuntu')
> with an IP address of 10.129.128.13 (ah yes the lucky one), a subnetmask 
> of 255.255.252.0 and a default gateway of 10.129.128.1.  That default 
> gateway takes me to the other subnets of the network without any problems.
> 
> I'm playing with NoMachine at the moment, trying to find better ways for 
> staff with broadband connections at home to use them to connect to our 
> terminal servers.  So what I'm trying to do is get an external ssh 
> session to come through the ipcop firewall (10.129.128.3) to 'ubuntu'.
> 
> It doesn't seem to work when the default gateway of 'ubuntu' is 
> 10.129.128.1.
> 
> If I change the default gateway on 'ubuntu' to 10.129.128.3 it works 
> well, but I can't see the rest of my network subnets.  Which for external 
> connections is fine, but if we start using it more regularly it'll be a 
> problem.
> 
> For consistancy's sake, I would like to the default gateway to be the 
> 10.129.128.1, but how do I also get a 'second default gateway' or at 
> least an intelligent route to the outside world?

OK, if I understand what you are saying correctly 10.129.128.1 is an
internal router.

If this is the case, then most likely you have all of your internal
routes to other subnets defined on this router.  However I am also
betting that 10.129.128.1 has its default route set to something other
than 10.129.128.3.

This means that 10.129.128.13 "knows" how to find your other internal
subnets via 10.129.128.1 and for Internet access from that machine I am
also guessing you use a proxy, hence why it can "see" the Internet under
normal circumstances just not when it need to route traffic other than
HTTP and friends.

So you should just be able to set 10.129.128.1's default route to
10.129.128.3 and things should "just work".

Of course I had less than two hours sleep last night...  So I could just
be making a 'stoopid Gawain' appraisal of the situation ;-)

Take care,

Gawain