Windows 7 x64 Ultimate desktop hard wired to Asus WL500gp router (WL500gpv2-22.214.171.124-d-r1445 firmware)
Several Bridged VirtualBox VM's running XP, 7, ubuntu server 10.04, Mint 9 and SuSE 11.2
Win XP Pro SP3 notebook with D-Link Airplus wireless network card.
No firewall or other security software currently running on either platform (at least for the duration of the test)
Router is acting DHCP server
Clients are receiving correct addresses and additional parameters
Internet connectivity is available from all clients
Windows 7 sharing is set to Network type = work (not home group)
NetBT is disabled on all clients using smb over TCP
What I can do:
I can ping the router and internet addresses from the wireless XP notebook
I can ping the Win 7 desktop and any VM from the XP wireless notebook
I can ping all devices from the router
All VM's and 7 can ping each other and the router as well as Internet addresses
What I can't do:
I cannot ping the XP wireless notebook from either the Win 7 desktop or the VM's; it always returns a destination host unreachable error. Tracert resolves the name or the XP notebook but also returns a destination host unreachable.
From the above it would seem that something is blocking connectivity in a single direction (from the Win 7 box to the Win XP notebook) only but the router can ping the XP notebook.
Some fresh input would be most welcome, as this is beginning to drive me batty.