When we replaced our ailing Airport Base Station with a Linksys WRT54GS, we had high hopes for trouble-free connectivity.
But alas, our G4 desktop, both of our iBooks, a MacBook and a PowerBook all had trouble getting the router’s DHCP server to give them IP addresses. It’s a problem I’ve had before, including in several Internet cafes with Linksys routers. I tried a lot: restarting the routers, fiddling with settings, trashing iBook preferences, swapping cables… nothing was working.
I was starting to reassemble the packaging for the Linksys and digging for the receipt when I decided to post my problems to the Mac OS X Hints forum. Within minutes – minutes I had the first reply. Soon, two Hall of Famers (whose usernames are TLarkin and Voldenuit) had me in hand.
Out of this came three valuable things:
- A troubleshooting strategy for WiFi connections;
- A suggestion that I try a dandy open-source replacement firmware called dd-wrt, which has crossed my radar before but definitely looks worth trying; and
- Quite by accident, the solution.
I was bracing myself for the full monty troubleshooting session when I decided to take one more shot at resolving things from the router’s control panel. And wouldn’t you know it…
The firewall was set to filter Port 113 (IDENT) — I don’t remember changing that setting, and wouldn’t have had any reason to, so I’m guessing that’s the default. Once I unchecked that option, all of our Macs — wired and wireless — began connecting and receiving IP addresses quite happily.
So there you go: stop filtering port 113 traffic, and your troubles might be over. (Of course, if someone has a cunning port 113 exploit, your troubles might just be beginning.) Otherwise, get ready for a long night of thorough troubleshooting.
