Hi Alex, Thanks for ther reply. I can't get to the URL (maybe I need an account?). Anyway, no worries. Yes I did think about using 2 separate interfaces, so I could try that.. I also know a small number of the companies using the same upstream, so I will try and catch them over the next few days and find out what gives and why I'm the only one having any issues. One other approach I could try is to see if I can obtain a range from the upstread off the 217.x.x.x range. No idea if there's availbaility, and it's a hassle reconfiguring all the systems (especially all the VOIP stuff) but that should work, I reckon. The "powers at be" are also suggesting I'm wasting too much time, if you know what I mean. 