Vdsm Network

Host Network Configuration

Vdsm defines a concept of “host network”. These networks are configured by the following Vdsm verbs:

  1. addNetwork Add the required Linux networking devices for a new network, as well as the configuration files required to re-create these devices on next boot.
  2. delNetwork Delete a previously-added network.
  3. editNetwork Replace an existing network definition by a new one.
  4. setSafeNetConfig Declare network configuration as “safe”, so it persists after host reboot.
  5. setupNetworks

Currently, host networks are implemented by Linux bridge devices, optionally connected to a vlan devices optionally connected to a bonding device, an optionally goes out of the host via a network interface card. Virtual machines connect to the bridge via a tap device.

Supported network topologies

bridge over interface card:

  bridge1 --------------------- nic

bridge over vlan over nic (bridge1(br) and bridge2(br2) represent two different networks):

  bridge1 --- v  ------------- nic
  bridge2 --- v2 ------------

bridge over bond over several nics:

  bridge1 ----------- bond --- nic1
                           -- nic2

(several) bridges over vlans over bond over nics:

  bridge1 --- v  --- bond --- nic1
                   /      \
  bridge2 --- v2 --        -- nic2

legless bridge (in-host only communication)