I accidentally rebooted my debian-based router this morning and now my computers that connect through it can no longer connect to the internet.

I imagine it has something to do with the apt-get upgrade I did a couple days ago. Probably some configuration file got changed but I'm not sure where to begin...

Right now, I can connect to the internet from my router just fine, and from my router to my other computers. I can connect to my router from the internet also. I can connect from my other computers to my router, but not from my other computers to the internet. As in:

lan computers <---> router
router <---> internet
lan computers (through router) <-x-> internet

I'm not at home right now which is how I'm able to post this.

I have several things running on my home router, like bind9, shorewall, and dhcpd. bind9 is used to intercept requests for my local network computers from the local network. I thought perhaps that was the problem and I turned it off but it didn't help.

If anyone has any ideas, I'd really appreciate it.

Thanks a lot,
- Andrew Clarke.

I figured this out. In /etc/shorewall.conf I had IP_FORWARDING=Keep which wasn't a problem. I must have upgraded something the other day that changed the default behaviour for IP_FORWARDING from ON to OFF. The only thing in my logs I can see that might have had something to do with that is dnsmasq.

Anyway, I now have IP_FORWARDING=On and it seems to be running fine.

- Andrew.