/ BLOG / Never doubt yourself

One of the users for the client that I mentioned in my last post works from home a fair bit, using a site-to-site IPSec tunnel that was setup a number of weeks ago, and a MacBook Pro running Leopard. As the rest of this client’s network is Windows based we hadn’t really considered restricting the Mac at all. After all this user is relatively clued up.. Or so I thought.

Tuesday we were told that the user was unable to access various resources on the LAN in the office. This was very odd as we could talk to the only other device on her subnet, which was her IP hard phone, without any problems. Even stranger her IP hard phone was working. We took her through the usual tests and everything seemed to be ok. I then incorrectly assumed that something had happened as part of the upgrade. The problem was this just didn’t make sense. If something had happened her IP phone wouldn’t work either. The lack of another machine at the tunnel end really hampered testing.

Much faffing and testing we come to the conclusion that it’s truly just her Macbook Pro. Further investigation reveals that PeerGuardian for OSX had been installed - which by default blocks almost all traffic. The moral is if something stops working, even if you know that you’ve changed something recently and you knew what you were doing properly, don’t waste too much time trying to figure out what you’ve done. Take a break and find out if it’s someone else’s fault first. If it still doesn’t make sense then it probably is you’ve caused.

I guess it’s a week of thoughts rather than technical stuff.