Re: Why unidirectional ping in LAN?

On Tue, 26 Jul 2005 12:51:39 -0600, "Chris Shearer Cooper" <chrisnews@xxxxxxx>
wrote:

>My LAN looks something like this, with R1 = normal router and R2 = wireless router :
>
>Internet ----- R ----- Desktop
> 1 --+
> |
>Nothing ------ R --+
> 2 ----- Laptop
>
>The problem I'm trying to figure out, is why the laptop can ping the desktop but not vice-versa.
>
>I'm imagining the ping from the laptop hits R2 who notices the destination address is inside the subnet, so he repeats that packet on all his LAN ports, one of which is R1. R1 sees the ping, notices the destination address is inside the subnet, so he repeats the packet on all his LAN ports, one of which is the desktop.
>
>So why doesn't it work the other direction? Is the fact that the laptop is connecting wirelessly relevant somehow?
>
>Thanks!
>Chris

Chris,

Is R2 running as a WAP right now? With both Desktop and Laptop on the same
subnet?

If that's true, then Desktop and Laptop are connected thru a pair of hubs /
switches. Switch functionality should direct the ping packet to the correct
port. There always could be a problematic switch / WAP component that's
defective, but just because Laptop is connected wirelessly, that's not a normal
possibility.

Try moving each computer to the other router, just temporarily. Make sure that
there's no problem with the router port / router. Try a new patch cable for
Desktop.

Other than a problem with one of the routers (in the switch / LAN side), I'd be
looking at a misconfigured / overlooked personal firewall:
<http://nitecruzr.blogspot.com/2005/05/troubleshooting-network-neighborhood.html#Security>

And look at corrupted LSP / Winsock:
<http://nitecruzr.blogspot.com/2005/05/problems-with-lsp-winsock-layer-in.html>

--
Cheers,
Chuck, MS-MVP [Windows - Networking]
http://nitecruzr.blogspot.com/
Paranoia is not a problem, when it's a normal response from experience.
My email is AT DOT
actual address pchuck mvps org.
.

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