Sorry, I did imply that you could not ping from behind a NAT router. That is not correct. What I should have stated is that the qemu virtual NAT network does not allow ping responses back from the outside. In fact the qemu documenation says that for all intents and purposes the virtual network has the functionality of a firewall that blocks this traffic.

Here is their representation of the virtual network.

By using the option `-user-net' or if you have no tun/tap init script, QEMU uses a completely user mode network stack (you don't need root priviledge to use the virtual network). The virtual network configuration is the following:

By using the option `-user-net' or if you have no tun/tap init script, QEMU uses a completely user mode network stack (you don't need root priviledge to use the virtual network). The virtual network configuration is the following:


QEMU Virtual Machine <------> Firewall/DHCP server <-----> Internet
(10.0.2.x) | (10.0.2.2)
|
----> DNS server (10.0.2.3)
|
----> SMB server (10.0.2.4)