I have been using Kerio 2.1.5 on my p.c., which is connected to the internet via a 4-port router. A couple of other p.c.s are also connected to the router. The system has been working fine for a year and I've been using BlitzenZeus's rules (slightly modified for my own situation). I've just changed my p.c. and reloaded all the software that I had on my old one. My OS is still XP Pro SP2, as before. My new p.c. can't seem to access the internet unless I unblock local ports 49152 - 65535. svchost.exe is now sending UDP datagrams from these ports to the router port 53. I never had this problem on my now discarded p.c. which is about six years old. Is it ok to leave these ports unblocked? Could it be the modern hardware spec of my new p.c. that's causing the difference?