Re: UDP packet being blocked

From: Gerald Vogt (
Date: 05/22/04

Date: Sat, 22 May 2004 19:19:10 GMT

JClark schrieb:

> I notice on my firewall log that an outgoing UDP packet is frequently
> being blocked. The source IP address is my IP address --
> router on a single computer -- and the destination address is
>, which is the IP address of my ISP, RoadRunner. The source
> port is 1137, the destination port is 53.
> I don't understand what this means. Why is an outgoing UDP packet
> going to my ISP and why is it being blocked? The system seems to be
> running OK.

Port 53 is DNS - Domain Name Service. It resolves the host names (e.g. to IP addresses (among other things). is most
likely the configured DNS server for your connection (check with
"ipconfig /all" in a command prompt) Basically any connection to the
internet (except those, that use an IP address directly) requires the
DNS server. My NIS 2004 (compared to 2003 I think) does not have a
general DNS rule anymore but allows DNS only for configured application.
So I assume, that you have a program running that tries to access the
internet and that you block. Check the logs to find out which program it