Redirection

It is also possible to achieve limited local connectivity even if you have no TAP support on your development machine. In redirection, QEMU essentially acts as a proxy, translating TCP or other connections and low-level packet operations on the network interface in the QEMU machine. For example, the following options will redirect the host's 9555 port to the QEMU machine's 80 port:

-net user -net nic,model=rtl8139  -redir tcp:9555:10.10.10.33:80

The first -net option indicates that we are using user-level networking (proxying). The second -net option indicates that this user-level network will appear in the QEMU machine as an RTL8139 network card. The -redir option indicates that connections on localhost:9555 will be translated into equivalent packet exchanges on the RTL8139 card in the QEMU machine. However, we have to tell QEMU which IP address and port to use on the QEMU machine's side. This is what the 10.10.10.33 address, and port 80 are. In the example, if you access port 9555 on localhost, say with:

telnet localhost 9555

The packets that appear in the QEMU machine will be bound for 10.10.10.33, port 80. Within the QEMU machine, your RTL8139 interface had better then be up on that address.

QEMU has many options to build up virtual or real networking. See http://www.h7.dion.ne.jp/$\sim$qemu-win/HowToNetwork-en.html for more information.

For more questions, talk to Jack, Lei, or Peter.