docs: Add instruction to set local_ip to ipsec tutorial.
Acked-by: Mark Gray
@@ -273,7 +273,26 @@ external IP is 1.1.1.1, and `host_2`'s external IP is 2.2.2.2. Make sure
authenticated; otherwise, any certificate signed by the CA would be
accepted.
-3. Test IPsec tunnel.
+3. Set the `local_ip` field in the Interface table (Optional)
+
+ Make sure that the `local_ip` field in the Interface table is set to the
+ NIC used for egress traffic.
+
+ On `host 1`::
+
+ # ovs-vsctl set Interface tun options:local_ip=$ip_1
+
+ Similarly, on `host 2`::
+
+ # ovs-vsctl set Interface tun options:local_ip=$ip_2
+
+ .. note::
+
+ It is not strictly necessary to set the `local_ip` field if your system
+ only has one NIC or the default gateway interface is set to the NIC
+ used for egress traffic.
+
+4. Test IPsec tunnel.
Now you should have an IPsec GRE tunnel running between two hosts. To verify
it, in `host_1`::
