Archived from groups: microsoft.public.windowsxp.work_remotely (
More info?)
"Stuffin" <Stuffin@nonsense.com> wrote in message
news:%MG2d.19863$ZC7.15535@newssvr19.news.prodigy.com...
>
> When trying to work with another user through Messenger, the other user
> requests Remote Assistance. I accept, but then get an error that says the
> other user's host name can't be resolved.
If the person requesting Remote Assistance is behind a NAT router, then that
router must have UPnP enabled, and Windows XP must be running the SSDP
Discovery Service (the default, though some users mistakenly switch it off).
This is required so that the remote assistance request application can
discover the true WAN IP address of the requester, rather than the local LAN
private IP address. The UPnP functionality of the router will look after
forwarding TCP port 3389 automatically.
If the person requesting Remote Assistance is running a firewall, then the
firewall must have the following open ports:
- TCP port 3389 from the internet (for the Remote Assistance inward call
from the expert);
- TCP port 2869 from the local subnet (for UPnP)
- UDP port 1900 from the local subnet (for UPnP)
If the firewall is the Windows Firewall, this can be accomplished by
checking the Exceptions for "UPnP Framework" and "Remote Desktop".
It should not be necessary to make any special router or firewall
configurations at the Expert end of the link.
--
Robin Walker [MVP Networking]
rdhw@cam.ac.uk