diff --git a/networking-qemu-kvm-howto.txt b/networking-qemu-kvm-howto.txt index 78d3f7e..d841200 100644 --- a/networking-qemu-kvm-howto.txt +++ b/networking-qemu-kvm-howto.txt @@ -42,3 +42,32 @@ QEMU networking tip ------------------- # printf 'DE:AD:BE:EF:%02X:%02X\n' $((RANDOM%256)) $((RANDOM%256)) # generates QEMU compatible mac addresses! + +------------------ +Bridged Networking +------------------ + +QEMU defaults to using NAT for its guests. It has a built-in DHCP server that +provides addresses from the 192.168.12x.0 subnet. However, this configuration +makes file sharing, printer sharing, and other common networking activities +harder to use in a home network. + +Bridged networking allows your QEMU guest to get an address on the same subnet +as the host computer. For example, many home networks let the wireless router +handle IP assignment via DHCP. Here are the steps for setting up the bridge. + +To setup bridged networking from the command line, refer to this documentation +at the Ubuntu website. https://help.ubuntu.com/community/KVM/Networking + +Ultimately, the script for booting the QEMU guest will need a line similar to +the following to enable bridged networking in the guest: + + -netdev bridge,id=net0,br=virbr0,"helper=/usr/lib/qemu/qemu-bridge-helper" + +On some systems the `qemu-bridge-helper` file has incorrect permissions. For it +to work, it needs to be setuid root. This can be accomplished with this command: + + $ sudo chmod u+s /usr/lib/qemu/qemu-bridge-helper + +Note that this is sometimes viewed as a security hole. Be careful and understand +what you are doing before running this command.