how to trace the icmp request on receiving machine

[summerdike]

How can I find out on a PC that is being pinged by another machine whether de icmp request is received or not?


(The icmp request sender does NOT receive reply, but maybe the icmp reply sender sends it to th "wrong" PC.).


______________________________
"Reload and Restart Requested
System Initiated"

 

[PalmTest]

Use Ethereal on the target machine. (

http://www.ethereal.com)

Start Ethereal.
In the menu, select "Capture" and then select "Options".
in the Capture section:
Select the right Interface.
Enter behind Capture Filter: icmp
Hit start.
A small window appears showing you the captured packets per protocol. All should remail zero at this point.

Do your ping test from one or more machines.

Stop the capture on the target machine.
As you will see the ICMP bar was filled.

Review the trace you made.

Tell us what you found out.

 

[summerdike]

I als thought about using Ethereal.
But as it is a domain server (in fact domain controller & router) that is involved I would rather not install network utilities on it like Ethereal.
So in fact I was looking for a lighter tool, but in the end Ethereal would surely do the job.

I first tried pinging from the router/server back to the pc.
Pinging (from server) did NOT return a reply from the PC.
So even if the ICMP request (ping) from the PC would reach the server, the server would not reply. I solved this by stating a static route on the server.
That solved the problem.





______________________________
"Reload and Restart Requested
System Initiated"

 

[PalmTest]

Sounds like your server is equipped with two NIC's.
Are they teamed?
Are the Default Gateway and the Subnetmasks correct on both NIC?

You can use a SPAN port on your switch and use Ethereal on a laptop to investigate the Ping problem.

Cisco:
Show monitor
config terminal
monitor session 1 destination interface 0/24
monitor session 1 source interface 0/2

This copies the traffic from int0/2 (your server on interface 2) to int0/24 (your laptop with ethereal on interface 24).
Use a Cisco Serial config cable because your laptop on interface 24 cannot use the network in a normal way because it is a destination port. Telnet and Ping do not work until the monitor sesson is ended.

To end monitoring:
config terminal
no monitor session 1 destination interface 0/24
no monitor session 1 source interface 0/2

You can also use packetyzer (

http://www.packetyzer.com)

This is the Ethereal engine with a Windows GUI, and some nifty features.