How to create bridge for InfraSIM

Two method to create a bridge:

• Create in commandline by brctl
• Edit /etc/network/interfaces and give control to OS

Create in commandline by brctl

Make <nic interface> to be a device just forward packet, and enable its promiscuous mode:

sudo ifconfig <nic interface> 0.0.0.0
sudo ifconfig <nic interface> promisc

Then leverage the <nic interface> to build your bridge <bridge name>:

sudo apt-get install bridge-utils
brctl addbr <bridge name>
brctl addif <bridge name> <nic interface>
brctl setfd <bridge name> 0
brctl sethello <bridge name> 1
brctl stp <bridge name> no
sudo ifup <bridge name>

Note: When creating bridge for InfraSIM, the current network connectivity will be disconnected.

Edit network interface

The file location is usually /etc/network/interfaces, you can refer to below example to define your bridge:

auto ens192
iface ens192 inet static
address 0.0.0.0
post-up ifconfig ens192 promisc

auto br0
iface br0 inet dhcp
bridge_ports ens192
bridge_fd 0
bridge_hello 1
bridge_stp off

Be careful about the line post-up ifconfig ens192 promisc, it makes PXE packet possible to go through ens192 and finally reach qemu. After you've written this file, run following command to restart your network:

sudo /etc/init.d/networking restart