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How can I create a virtual network interface like virbr0-nic? I am trying to find a way to create a NIC like virbr0-nic but everything which I can find on the Internet is how to create an interface attached to the physical interface like eth0:0. When I write

# brctl show
bridge name bridge id       STP enabled interfaces
virbr0      8000.525400e0af01   yes virbr0-nic
virbr1      8000.525400e8a6b1   yes virbr1-nic

So virbr0 is the bridge to which virbr0-nic is attached. So how are virbr0-nic and vnet1 created?

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usually that's associated with something like a bridge specific to a bit of software. What're you REALLY trying to do? –  Journeyman Geek Jun 17 '13 at 14:54
I have installed KVM and noticed that it created new NIC virbr0-nic. I am just wondering how can I create my own NIC such as this one. –  cosimo Jun 17 '13 at 15:30

2 Answers 2

These are dummy devices. You can run

modprobe dummy

To create a network interface called dummy0.

If you want more than one device, you can create say 5 with

modprobe dummy numdummies=5

You can then control these devices like any other network device.

Give it a MAC address with

ip link set dummy0 address aa:aa:aa:bb:bb:bb

Give it an IP address with

ip addr add dev dummy0

Add it to your existing bridge with

brctl addif virbr0 dummy0

Set it up, set it down, NAT off it, and so on.

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virbr0-nic stands for Virtual bridge NIC.

It's basically a bridge between your physical Network Card and your Virtual Machine's virtual Network Card.

To manage bridged interface you can use the brctl command. You can list all your bridged interfaces with

brctl show

and add or modify bridges accordingly to your needs. To create a new bridge use

brctl addbr

where will be your new bridge's name (as virbr0-nic).Then you can add interfaces to the bridge with

brctl addif .

You can refer to the man page for additional information.

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