diff --git a/docs/chapters/subcommands/rdr.rst b/docs/chapters/subcommands/rdr.rst
index a65375a2..ac7af3c6 100644
--- a/docs/chapters/subcommands/rdr.rst
+++ b/docs/chapters/subcommands/rdr.rst
@@ -24,3 +24,17 @@ specify the interface they run on in rc.conf (or other config files)
     rdr on em0 inet proto udp from any to any port = 2053 -> 10.17.89.1 port 53
     # bastille rdr dev1 clear
     nat cleared
+
+If you have a host with multiple interfaces, and you want to specify which
+one to use, `bastille rdr` allows you to pass any interface to the command.
+If you do not specify an interface, the default one will be used.
+
+.. code-block:: shell
+
+    # bastille rdr em0 dev1 tcp 2001 22
+    # bastille rdr dev1 list
+    rdr on em0 inet proto tcp from any to any port = 2001 -> 10.17.89.1 port 22
+    # bastille rdr dev1 vtnet0 udp 2053 53
+    # bastille rdr dev1 list
+    rdr on em0 inet proto tcp from any to any port = 2001 -> 10.17.89.1 port 22
+    rdr on vtnet0 inet proto udp from any to any port = 2053 -> 10.17.89.1 port 53