Firstly to note that I had a look in the forums, but I couldn't find an answer to my problem. If anyone knows a thread that covers the issue, please tell me instead of wasting time in writing an answer.
Well, I have FC3 installed on a standard PC with two network cards. My computer is acting as a router for my home LAN, so that my housemates can access Internet through our ADSL connection. One of my network cards is connected to a ADSL modem, and the other one is going to a switch, to which everyone else is connected.
The problem that I have is that sometimes (I can't find a common case) the other computers connected to the switch cannot use the network at all. Not only Internet, but they can't access my computer as well. Usually it works (especially after a reboot or a network service restart), but sometimes it doesn't. It happens with both Windows XP and with Mac OSX Panther.
I let Firestarter configure the dhcpd server on my machine and it seems that it is working quite good, and retarting the dhcpd service does not solve the problem. If I do a network restart (service restart) though, the other computers can find mine and can obtain IP addresses from the dhcpd server.
Firstly I thought that it may be something like overloading the arp cache when I am downloading bittorrents, but I am not too sure that can happen (any thoughts on that will be appreciated) and also I was thinking that it may be a hardware problem (but I don't know if restarting the network resets the hardware).
When I am doing restarts I mean:
$service network restart, and
$service dhcpd restart
with my root account.
I will be very happy to get help of any kind.