"Detination unreachable" packets

[Josef Jirkovsky]

Hi,

my question is perhaps off-topic but i'm trying anyway.

I'm tracing packets going in and out and i have a great number
of ICMP packets coming in to my L1000 what i identified
as "destination unreachable" packets.
The source IP address is always 195.83.192.18 (since i am tracing) with source port 3
and the destination is my L1000 IP address with
destination port 13.
I have no outgoing packets with the IP address 195.83.192.18.

Anybody knows what's going on, or how to stop this traffic, and why all that?

Thanks,
josef

[Ron Kinner]

195.83.192.18 is probably your local router or perhaps that of your ISP. ICMP packets are slightly different from TCP so you don't really have a port. What you have is a Type field. See:

http://www.erg.abdn.ac.uk/users/gorry/course/inet-pages/icmp-code.html

for a list of the different types. If you check the next 8 bits after the 8 bit field with Type 3 you will see the reason Code which explains why the destination could not be reached.

Your box is sending something out to another destination which eventually gets passed to 195.83.192.18 but which 195.83.192.18 is unable to route further. If you run a traceroute you will probably see that 195.83.192.18 shows up in the normal course of the trace.

Ron