Software Firewall Problem

[dracan]

Hi. I'm using Sygate Personal Firewall. However some parts of sites are getting blocked. One for example, is the login page of EBay (note this is just an example, many more sites do the same). If I disable SPF, then it works fine. Looking at the firewall logs, I get the following:

27800 07/24/2005 11:00:49 Allowed 10 Outgoing TCP signin.ebay.co.uk [66.135.198.195] 00-0F-B5-79-D1-36 80 192.168.0.2 00-00-21-2A-2E-9B 1115 C:\Pro
ram Files\Mozilla Firefox\firefox.exe Dan HOME Normal 1 07/24/2005 11:00:47 07/24/2005 11:00:47 GUI%GUICONFIG#SRULE@APPCONFIG-TCP#C:\Program Files\Mozilla Firefox\firefox.exe

27801 07/24/2005 [66.135.198.195] 00-0F-B5-79-D1-36 80 192.168.0.2 00-00-21-2A-2E-9B 1115 C:\Pro
ram11:02:02 Blocked 10 Incoming ICMP 192.168.0.1 00-0F-B5-79-D1-36 4 192.168.0.2 0
-00-21-2A-2E-9B 3 Dan HOME Normal 2 07/24/2005 11:00:50 07/24/2005 11:00:57 Block_all

The outgoing packets seem to be going out fine. It's the incoming packets that are getting blocked. The incoming packet seems to be coming from remote port 4, and it's target port is port 3. I don't understand why these ports are being used? Any ideas why these ports are being used? Or how I can get Sygate to allow these through?

Thanks for any info,
Regards,
Dan.

ps. It's just done exactly the same when trying to post this topic. I've just had to disable the firewall to be able to post it

 

[dracan]

If anyone's interested, I found out what the problem was. If the MTU of my PC is greater than that of my router, some packets will get rejected by the router. The router will the return the packet to the PC using port 3 and 4. I fixed the problem by altering my computer's MTU to match that of my router.