I'm using WinXP with an ADSL connection. Recently I've found a lot of inbound ICMP traffic (12 connections every 25 sec, it filled up my log file pretty fast so I can only see the last three hours). They all come from my gateway and the remote port shows "destination unreachable/3".

I'm using the Agnitum Oupost firewall with the ICMP settings (default):
Echo reply 0 (IN)
Destination unreachable 3 (IN)
Echo request 8 (OUT)
Time eceeded for a datagram 11 (IN)
all other ICMP connections are disabled.

I'm not sure what ICMP is, but I get a bit worried about all this traffic. Is there a reason for me to be alarmed?

Thankful for any comments.

Is MSN Messenger running or any Message Program when you get the ICMP alert.

Usually at that high rate. ICMP can do alot of things usually to keep-alive a chat connection from the server.

Just my thoughts

Well, it was that simple... MSN Messenger was running, when I closed it, the ICMP traffic stopped.

Thanks!