From 1ab9712b8936d175457121a4812a087ba9fa87fb Mon Sep 17 00:00:00 2001 From: Ben Pfaff Date: Tue, 23 Apr 2013 09:30:14 -0700 Subject: [PATCH] FAQ: Describe how to connect bridges with patch ports. I keep seeing this question. Signed-off-by: Ben Pfaff --- FAQ | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/FAQ b/FAQ index 186f3ac4a..a8e377237 100644 --- a/FAQ +++ b/FAQ @@ -325,6 +325,43 @@ A: No. ERSPAN is an undocumented proprietary protocol. As an alternative, Open vSwitch supports mirroring to a GRE tunnel (see above). +Q: How do I connect two bridges? + +A: First, why do you want to do this? Two connected bridges are not + much different from a single bridge, so you might as well just have + a single bridge with all your ports on it. + + If you still want to connect two bridges, you can use a pair of + patch ports. The following example creates bridges br0 and br1, + adds eth0 and tap0 to br0, adds tap1 to br1, and then connects br0 + and br1 with a pair of patch ports. + + ovs-vsctl add-br br0 + ovs-vsctl add-port br0 eth0 + ovs-vsctl add-port br0 tap0 + ovs-vsctl add-br br1 + ovs-vsctl add-port br1 tap1 + ovs-vsctl \ + -- add-port br0 patch0 \ + -- set interface patch0 type=patch options:peer=patch1 \ + -- add-port br1 patch1 \ + -- set interface patch1 type=patch options:peer=patch0 + + Bridges connected with patch ports are much like a single bridge. + For instance, if the example above also added eth1 to br1, and both + eth0 and eth1 happened to be connected to the same next-hop switch, + then you could loop your network just as you would if you added + eth0 and eth1 to the same bridge (see the "Configuration Problems" + section below for more information). + + If you are using Open vSwitch 1.9 or an earlier version, then you + need to be using the kernel module bundled with Open vSwitch rather + than the one that is integrated into Linux 3.3 and later, because + Open vSwitch 1.9 and earlier versions need kernel support for patch + ports. This also means that in Open vSwitch 1.9 and earlier, patch + ports will not work with the userspace datapath, only with the + kernel module. + Q: Why are there so many different ways to dump flows? A: Open vSwitch uses different kinds of flows for different purposes: -- 2.43.0