Debugging Openvswitch¶
Listing all the flows present in vswitch¶
This is the default flow present which allows all the traffic.
[root@compute-202-tammy libvirt]# ovs-ofctl dump-flows br-cache
NXST_FLOW reply (xid=0x4):
cookie=0x0, duration=2005.504s, table=0, n_packets=1435, n_bytes=133878, idle_age=216, priority=0 actions=NORMAL
[root@compute-202-tammy libvirt]#
When a vlan tag is added to a particular port¶
Let’s add a vlan tag to the nic of vm attached to openvswitch. This can be achieved by adding this to the libvirt XML:-
<interface id=...>
...
<vlan>
<tag id='2001'/>
</vlan>
...
</interface>
This puts the vm on vlan 2001.
# ovs-vsctl show
Bridge br-cache
Port br-cache
Interface br-cache
type: internal
Port cache-sxyurrqj
tag: 2001 <----- tagged with vlan 2001
Interface cache-sxyurrqj
Port cache-taoogliq
tag: 2002 <----- tagged with vlan 2002
Interface cache-taoogliq
Port cache-etqzozoc
tag: 2002 <----- tagged with vlan 2002
Interface cache-etqzozoc
Port cache-uoildwal
tag: 2001 <----- tagged with vlan 2001
Interface cache-uoildwal
To tag the port as trunk and add multiple vlans, one can use:
<vlan trunk='yes'>
<tag id='2001'/>
<tag id='2002'/>
<tag id='2003'/>
</vlan>