Ok, long story short, my firewall script and pptp connection hate eachother. I connect my pptp connection,and the firewall begins blocking everything until it is restarted. I disconnect, and the same problem occurs. I've poked and prodded at the issue for a few hours, and at this point just want a quick fix, since the box is being replaced/reloaded in under a month. So, how can I have my Linux machine run a script the instant it sees a new interface appear, or disappear? I would do it manually, but the problem is that at times, I connect the PPTP session remotely, and cannot get the firewall script to run again if the connection drops without warning.