LAN/WAN Connection degrades over time.
I just setup pfSense a few days ago and I seem to keep having the same problem even after multiple reinstalls. The system pfSense is installed on is a PIII 500 with 192MB ram and 1.6 GB HD, with two NIC's both using the rl driver. The LAN nic is connected to a 10/100 switch.
The problem I am having is after a short amount of time (15 - 20 mins) both the LAN and WAN connection starts to degrade. The switch shows that there is constant activity on the network even though the only computer connected to it is doing nothing over the network. The connection will continue to degrade to the point where I can not access the web interface on the pfSense box. I can still access the internet, but at a very slow speed, eventually after a little more time I will not be able to access the internet. If I connect my computer directly up to the DSL modem the connection works just fine. I have tried two Intel 82558 nic's, which use the fxp driver, in the pfSense box to rule out hardware. But the problem still occurs. I have even tried another switch, and the same thing happens. I can't figure out what is happening.
If anymore info is needed I can provide it.
Try using Intel NICS.
Make sure your hosts are really doing nothing. This somehow sounds like one of your hosts is a bot starting to cause massive packet load. View pftop from the console of the pfsense when that happens again to see what's going on on your network.