I have the W7 64bit Host Vox4.1.8 and two OL5.7 64bit Guests, Say G1&2.
The Host Only Network has been setup for the guests.
there have been the applications deployed on the both guests. all have been running no problem for a few months.
Now I have found no ports on the G1 are visible to the W7 Host, which was not the case before:

I can ping G1 server IP but no ports of G1 can be accessed from W7 Host;
I can access all the ports of G2 from W7 Host;
From G2 I can access all the ports of G1, and From G1 I can access all the ports of G2;
All the applications on G1 are running normal. I access the Host and Internet from G1 no problem.

I tried to turn off the firewall of the host but no luck.

I am not sure what have canaged on G1 since last reboot.

Please help with the troubleshoot.