Networking Guide

4 Click the Add button and from the drop-down menu, choose one of the following options:
Option Description
Source NAT (SNAT)
An SNAT rule changes the source IP address and, optionally, port of
outgoing packets. When you create an SNAT rule in vCloud Air, by
default the port and protocol are set to “any.” To change the default the
port and protocol settings for an SNAT rule, edit the settings in
vCloud Director.
Destination (DNAT)
A DNAT rule changes the destination IP address and, optionally, port of
inbound packets.
5 Depending on which type of NAT rule you are creating, complete the following settings:
Source NAT (SNAT) (inside -> outside)
Option Description
Original (Internal) Source
Enter the original IP address or range of IP addresses to apply to this rule.
These addresses are the IP addresses of the virtual machine (or machines)
for which you are configuring SNAT so that they can send traffic to the
external network.
Translated (External) Source
Specifies the IP address to which source addresses (the virtual machines)
on outbound packets are translated to when they send traffic to the
external network.
This address is always the public IP address of the gateway for which you
are configuring the SNAT rule.
Select the required IP address from the drop-down list.
Destination NAT (DNAT) (outside -> inside)
Option Description
Original (External) IP
Specifies the destination IP address to which the rule applies; this address
is always the public IP address of the gateway for which you are
configuring the DNAT rule.
Select the required IP address from the drop-down list.
Protocol
Select the protocol to which the rule applies—any, TCP, UDP, TCP/UDP,
and ICMP. By default, the protocol is set to “any.”
Original Port/Range
(Optional) Enter the port or port range that the incoming traffic uses on the
gateway to connect to the internal network on which the virtual machines
are connected.
ICMP type
If you selected ICMP (an error reporting and diagnostic utility used
between devices to communicate error information) in the Protocol field,
select the ICMP type from the drop-down menu. ICMP messages are
identified by the “type” field. By default, the ICMP type is set to “any.”
Translated (Internal) IP/Range
Enter the IP address or a range of IP addresses to which destination
addresses on inbound packets will be translated.
These addresses are the IP addresses of the virtual machine (or machines)
for which you are configuring DNAT so that they can receive traffic from
the external network.
Translated Port/Range
(Optional) Enter the port or port range that traffic connects to on the
virtual machines on the internal network.
6 Select Enable this rule and click Save.
Chapter 2 About Managing Gateways and Networks
VMware, Inc. 25