Hi there, My ISP (cable) had some problems today. Therefore I rang them up and asked how long the (unknown) problem would take to fix. The technician auto-assumed that the problem was on my side (don't they always) but still started to check various things from their side and asked a lot of random questions. The ISP problems mysteriously disappeared 3 mins into the conversation (without me changing anything on my setup or configuration), but the technician still insisted that the problem was not on their side. Anyway, one of his questions was if I was running any kind of firewall. And I am not. So on to my question: Is it advised that I enable the built in Firewall of 10.5.5 or any 3rd party one? By doing so, would I loose any functionality, or would anything get blocked that one might need? If it matters: My setup consists of a cable modem that is connected to a wireless thingy. And then there is the MacBook which is connected wirelessly to that. hope someone can shed some light on this, please.