[Rack] Port forwarding for Mode-S testing

[Andy Isaacson]

I've added another NAT rule to bikeshed.  The config currently looks
like:

adi at bikeshed# show service nat 
 rule 1 {
     destination {
         address 75.101.62.93
     }
     inbound-interface eth2
     inside-address {
         address 172.30.0.50
     }
     type destination
 }
 rule 2 {
     destination {
         address 199.188.193.145
         port 9742
     }
     inbound-interface eth0
     inside-address {
         address 172.30.0.53
         port 9742
     }
     protocol udp
     type destination
 }
+rule 3 {
+    destination {
+        address 75.101.62.88
+        port 9742
+    }
+    inbound-interface eth2
+    inside-address {
+        address 172.30.0.53
+        port 9742
+    }
+    protocol udp
+    type destination
+}
[edit]

I believe this will make the Mode-S UDP protocol on port 9742 continue
to work when the Vayatta auto-failover switches the interfaces around.

(I've committed the config, the above was from the pre-commit display.)

-andy