====== Openvswitch (OVS) tips & trips ======

<note important>**Before anything - RTFF - [[http://git.openvswitch.org/cgi-bin/gitweb.cgi?p=openvswitch;a=blob_plain;f=FAQ;hb=HEAD|FAQ (Frequently Asked Questions)]]**</note>

===== Installation/compile =====

==== Debian / from source / GIT ====

   export DEB_BUILD_OPTIONS=nocheck
   dpkg-buildpackage -b -us -uc -nc

===== Configuration tips =====
==== Configuration in Debian/Ubuntu via /etc/network/interfaces ====
Example:
<code|/etc/network/interfaces>
allow-ovs br0
iface br0 inet manual
   ovs_type OVSBridge
   ovs_ports mgt0 eth1 eth2
   ovs_extra set Bridge br0 stp_enable=true
  
allow-br0 mgt0
iface mgt0 inet static
    address 10.14.131.34
    netmask 255.255.255.224
    ovs_bridge br0
    ovs_type OVSIntPort
    ovs_options vlan_mode=access
    ovs_options tag=999

allow-br0 eth1
iface eth1 inet manual
    ovs_bridge br0
    ovs_type OVSPort
    ovs_options vlan_mode=native-untagged
    ovs_options trunks=10,20,30,40
    ovs_options tag=999

allow-br0 eth2
iface eth2 inet manual
    ovs_bridge br0
    ovs_type OVSPort
    ovs_options vlan_mode=trunk
    ovs_options trunks=30,40
</code>

==== Creating GRE tunnel ====
<code|/etc/network/interfaces>
allow-ovs br0
iface br0 inet manual
   ovs_type OVSBridge
   ovs_ports mgt0 eth1 
   ovs_extra set Bridge br0 stp_enable=true
   post-up ovs-vsctl add-port br0 vgre0 -- set interface vgre0 type=gre \
	 options:remote_ip=10.0.0.1
....
</code>

===== Frequently use (useful) command =====

# Dump flows

   ovs-ofctl dump-flows br0

# Show mac table

   ovs-appctl fdb/show br0

# Show switch

   ovs-vsctl show

# Show datapath

   ovs-dpctl show

# Turn debugging on

   ovs-appctl vlog/set dbg

===== Troubleshooting =====

==== GRE problem ====

"You need to unload ''**ip_gre**'' and ''**gre**'' module, openvswitch GRE does not work along with kernel GRE module for now."