no remote pinging for one wan address

Kindly, we have two laptops connected through two gateways with two m2m sim cards (https://en.wikipedia.org/wiki/Machine_to_machine), as follows.


Laptop1 (LAN 192.168.100.1)
to
Gateway1 (LAN 192.168.100.211) (WAN 10.28.76.3)
to
M2M network (cellular)
to
Gateway2 (LAN 192.168.100.212) (WAN 10.28.76.2)
to
Laptop2 (LAN 192.168.100.2)


From Laptop1, we can ping Gateway2 (WAN 10.28.76.2).
But from Laptop2, we cannot ping Gateway1 (WAN 10.28.76.3).
Even if we exchanged any part, no remote pinging is possible for (WAN 10.28.76.3).

Check below Ping and Tracert results.

ping 10.28.76.3
Pinging 10.28.76.3 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Ping statistics for 10.28.76.3:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss)


tracert 10.28.76.3
Tracing route to 10.28.76.3 over a maximum of 30 hops
1 * * * Request timed out.
2 * * * Request timed out.
3 * * * Request timed out.
4 * * * Request timed out.
5 * * * Request timed out.




Any ideas why is this happening?

Thank you

Check all your firewall rules, network masqe settings, ICMP handling,etc. You can easily block a ping request (its a special packet than can be recognized and ignored by routers, etc).

I tried with Firewall off, same problem.

The strange thing is that remote pinging of the other sim card (WAN 10.28.76.2) is always running, from any laptop, with any gateway!

Make sure that Gateway 2 is able to respond to pings. A lot of network equipment can be configured to disable the ping response as a security feature. I would then get a separate laptop with a simple hub (I switch won't do it unless you can mirror the ports) and connect to Gateway 2 and see if it's seeing the ping request or not. Work backwards from there.

I second what Firejo said about the gateway not responding to pings.

What kind of gateway are you using ? Is it an actual router, or a layer 3 switch ?

Can laptop 2 ping anything else ? Can it at least ping gateway 2's LAN address ?

It is a ProSoft ICX35-HWC gateway.
Yes, i can ping anything from any laptop.
The only exception is no pinging of 10.28.76.3 through the gateways (remotely).

Solved!
We got a third sim card 10.28.76.4 and it worked fine with the sim card 10.28.76.3

Strangely the bad sim card 10.28.76.2 is only pinging well on mobile phones, it does not like ProSoft gateways...

Kataeb said:

Solved!
We got a third sim card 10.28.76.4 and it worked fine with the sim card 10.28.76.3

Strangely the bad sim card 10.28.76.2 is only pinging well on mobile phones, it does not like ProSoft gateways...

Click to expand...

That's an interesting fix but thanks for letting us know what the solution was.