I have posted this problem in the Sunbelt support forum, but I wanted to also post it here, in case any others are having this issue: Product: Sunbelt Personal Firewall Free Edition System version 126.96.36.199.0 Rules version 188.8.131.52 The following logged message happened so many times that I was forced to reboot both modem and router: ICMP PATH MTU denial of service" from my router ( IP: 192.168.1.2 ). I first made the attempt to put a range of ip masks in as "Trusted", but that did no good. I then was forced to edit one of the config files in order to remove the rule. It seems to me that this is a pretty healthy bug in this firewall. Free or not, there MUST be a way to edit the ruleset without compromising security. When will the option to ignore router addy be put in? Or when will the rule editor be turned on? Either one of these options would have solved this issue without having to take down the entire system. Other than that, I do like the firewall, I would just prefer that such an obvious bug be taken care of, maybe thru a patched update?