Currently, I have two networks configured via xml:

virsh # net-dumpxml TestNetwork1
<network connections='2'>
  <name>TestNetwork1</name>
  <uuid>a76f665a-0196-4edb-81b4-340944a6869c</uuid>
  <forward dev='p1p1' mode='nat'>
    <nat>
      <port start='1024' end='65535'/>
    </nat>
    <interface dev='p1p1'/>
  </forward>
  <bridge name='virbr0' stp='on' delay='0'/>
  <mac address='52:54:00:0b:e9:35'/>
  <ip address='192.168.100.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.100.128' end='192.168.100.254'/>
    </dhcp>
  </ip>
</network>

virsh # net-dumpxml default6
<network connections='1'>
  <name>default6</name>
  <uuid>6e57d831-f09e-4b33-950d-6d51c89f9786</uuid>
  <forward mode='nat'/>
  <bridge name='virbr3' stp='on' delay='0'/>
  <mac address='52:54:00:cb:c5:50'/>
  <ip family='ipv6' address='2001:db8:ca2:2::1' prefix='64'>
    <dhcp>
      <range start='2001:db8:ca2:2:1::10' end='2001:db8:ca2:2:1::ff'/>
    </dhcp>
  </ip>
</network>

# brctl show
bridge name bridge id STP enabled interfaces
virbr0 8000.5254000be935 yes virbr0-nic
vnet0
vnet1
virbr3 8000.525400cbc550 yes virbr3-nic
vnet2

My queries are:
(i) For each interface that I attach to my guests, will a new vnetX (X=0,1,2,3,...) be created?
(ii) Can two different active networks share the same bridge? Example, can the xml of two active networks have the same line <bridge name='virbr0' stp='on' delay='0'/> ?
(iii) If the answer for (ii) is false, how can I obtain the interface name for a given bridge name in libvirt?



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Nehal J Wani