Network routing with two networks which don't like each other

I have an interesting situation at work. I bring my MacBook Pro in from home because it's the most suitable machine for what I do. At work I have access to two networks as follows:

Network 1: Wireless direct to the internet, but cannot access internal servers such as company email which is only accessible internally.

Network 2: Ethernet which gives me access to company servers such as email, but limited access to the internet. For example I cannot access any of my IMAP email servers through it.

This creates a situation where I'm constantly activating and deactivating the wireless to get access to things. If I want my private email I have to activate the wireless to get it. But then I cannot access any company servers such as work email. If I deactivate the wireless I can then access the company servers, but now cannot get to all external servers.

Any suggestions as to how I can configure the system to be able to access both networks and to know which servers are available through each connection? or perhaps to be able to query one connection and then the other if the first says server not found?

drekka

Posted 2012-03-20T00:41:24.310

Reputation: 196

Please specify what operating system you use on your Macbook. – Eroen – 2012-03-20T00:52:25.247

Mac OS X 10.7.n – drekka – 2012-03-20T02:03:54.487

Answers

Have you discusssed with your IT/IS department? The wireless may be configured to only allow external acess unless it is authorized or authenticates properly. One phone call may asssit.

Dave M

Posted 2012-03-20T00:41:24.310

Reputation: 12 811

No, the wireless is not officially supported. The main network is heavy locked down and has done pain in the but proxies as well. So I'm looking to see if there is anything I can do on the Mac to deal with two connections. – drekka – 2012-03-20T02:03:47.450

Have both nets (interfaces) up
route add ... (if this command still exist in OSX) in order to add correct routes to needed nets over correct interface
In extremely bad case route change 0.0.0.0 ... in order to change default gateway

Don't fool IT-boys!!!

Lazy Badger

Posted 2012-03-20T00:41:24.310

Reputation: 3 557

That helped a bit. As long as I have the correct IP it routes and I can access the box. But if I don't and need a DNS resolution I get nowhere. I've tried adding files to /etc/resolver but so far they don't seem to be working. – drekka – 2012-03-20T07:10:27.427

@DerekClarkson - add only specific routes to networks (which you have to pre-identify) and permanent route to IP of external DNS-server – Lazy Badger – 2012-03-20T07:20:49.313

Not sure I exactly follow that @LB. So far I know the IP of the internal servers and I've been able to setup a route so that anything with that IP goes to the ethernet. The problem I have at the moment is that I cannot get multiple DNS lookups. I've added the internal DNS servers to /etc/resolvers but it does not seem to be working. Still trying to figure out how to debug that. – drekka – 2012-03-20T23:15:39.840

@DerekClarkson - " multiple DNS lookups" please explain, that is it – Lazy Badger – 2012-03-21T01:20:21.277

Ahh, ok. I mean configuring the system so that it can use multiple DNS name servers from different providers. for example, the name servers on the company LAN know where the company servers are where as the name servers on the wireless have no idea. This is actually more complicated by the fact that both connections know about <company>.com.au, but I only want the resolution from the ethernet because they are inside the LAN, whilst the wireless one goes to the public site. – drekka – 2012-03-21T05:37:41.187

I think this problem is going to be too hard to solve without adding a 3rd party localhost based DNS server and I'm not really wanting to do that. – drekka – 2012-03-21T05:38:43.227

@DerekClarkson - two DNSes (and LAN DNS is first)? Unresolved requests from 1-st (if I'm correct) will go to second – Lazy Badger – 2012-03-21T05:51:14.073

The tricky part is that both DNSs can resolve the domain. I need to be able to specify a domain to DNS relationship because in some cases it's the wireless one I want, in others it's the LAN. – drekka – 2012-03-22T00:23:50.780