Ping from PocketPC

[eekvang]

Hi all.

I have created a small utility for Windows Mobile 5.0 based Pocket PC.
The utility allows me to ping any host by sending an ICMP packet an
receiving a reply from the specified host.

For some reason when the device is connected to the internet through
ActiveSync a reply is not received from any host. The utility works as
expected when it is connected using WLAN or UMTS/GPRS connection.
I have tried using the emulator inside VisualStudio, but the same
happens here. I know that the device/emulator is connected to the
internet because I can access the web-page I am trying to ping through
Internet Explorer.

Anyone experienced the same problem? Ant suggestions?

Thank you

Espen Ekvang

 

[Paul G. Tobey [eMVP]]

I think that you have there a limitation of ActiveSync. It doesn't want to
be a forwarder of every conceivable packet on Earth. It's designed to allow
most, if not all, TCP and UDP traffic to be sent/received from whatever
remote network the PC is connected to, but I'd be very surprised if ICMP was
among those. In fact, I'd think that ICMP is probably not going out. You
could check that with a network sniffer on the other side of the PC's
network card. You could try changing the TTL value in your ICMP packets,
but, again, it's up to ActiveSync what it allows.

Paul T.

 

[Bryan Phillips]

It sounds like the ICMP packet is being dropped by a firewall on the
ActiveSync installed computer or on the network. Can you eliminate this
as a possible cause?

Bryan Phillips
MCSD, MCDBA, MCSE
Blog: http://bphillips76.spaces.live.com

 

[Guest]

ActiveSync doesn't relay ICMP, so it's not a firewall, but ActiveSync
itself.

-Chris

 

[eekvang]

Thanks for your replies.
Since ActiveSync does not relay ICMP it would be useful for me to be
able to test whether a device is connected using ActiveSync or not. Is
this possible?

Espen

 

[Guest]

If you are connected via ActiveSync the hostname PPP_PEER will resolve.