Describe dummy test model. Work on OpenFlow intro.

[openvswitch] / INSTALL.userspace

diff --git a/INSTALL.userspace b/INSTALL.userspace
index c13365a42090fe86f61990b9d9eb41ceffdecbdf..296f0771c6f4cf3adaa3ab5d5fc35951c5788a61 100644 (file)
--- a/INSTALL.userspace
+++ b/INSTALL.userspace
@@ -17,7 +17,7 @@ Building and Installing
 -----------------------
 
 The requirements and procedure for building, installing, and
-configuring Open vSwitch are the same as those given in INSTALL.Linux.
+configuring Open vSwitch are the same as those given in INSTALL.
 You may omit configuring, building, and installing the kernel module,
 and the related requirements.
 
@@ -31,6 +31,10 @@ The tun device must also exist as /dev/net/tun.  If it does not exist,
 then create /dev/net (if necessary) with "mkdir /dev/net", then create
 /dev/net/tun with "mknod /dev/net/tun c 10 200".
 
+On FreeBSD, the userspace switch additionally requires the kernel
+tap(4) driver to be available, either built into the kernel or loaded
+as a module.
+
 Using the Userspace Datapath with ovs-vswitchd
 ----------------------------------------------
 
@@ -47,17 +51,18 @@ ovs-vswitchd will create a TAP device as the bridge's local interface,
 named the same as the bridge, as well as for each configured internal
 interface.
 
-Using the Userspace Datapath with ovs-openflowd
------------------------------------------------
-
-To use ovs-openflowd in userspace mode, specify a datapath name that
-begins with "netdev@", and specify --ports with the names of the ports
-that should be included in the datapath as argument.  For example:
+Firewall Rules
+--------------
 
-    ovs-openflowd netdev@br0 --ports=eth0,eth1,eth2
+On Linux, when a physical interface is in use by the userspace
+datapath, packets received on the interface still also pass into the
+kernel TCP/IP stack.  This can cause surprising and incorrect
+behavior.  You can use "iptables" to avoid this behavior, by using it
+to drop received packets.  For example, to drop packets received on
+eth0:
 
-ovs-openflowd will create a TAP device as the bridge's local
-interface, named the same as the bridge minus the "netdev@" prefix.
+    iptables -A INPUT -i eth0 -j DROP
+    iptables -A FORWARD -i eth0 -j DROP
 
 Bug Reporting
 -------------