Network Router User Manual

SmartSwitch Router User Reference Manual 229
Chapter 16: Network Address Translation Configuration Guide
Using Dynamic NAT with DNS
When a client from outside sends a query to the static global IP address of the DNS server,
NAT will translate the global IP address to the local IP address of the DNS server. The
DNS server will resolve the query and respond with a reply. The reply can include the
local IP address of a host inside the local network (for example, 10.1.1.2); this local IP
address will be translated by NAT into a global IP address (for example, 192.50.20.2) in a
dynamic binding for the response.
Dynamic NAT with Outside Interface Redundancy
The following example configures a dynamic address binding for inside addresses
10.1.1.0/24 to outside addresses 192.50.20.0/24 on interface 192-net and to outside
addresses 201.50.20.0/24 on interface 201-net:
The first step is to create the interfaces:
Next, define the interfaces to be NAT “inside” or “outside”:
et.2.2
(201.50.20.0/24)
et.2.1
(10.1.1.1/24)
IP network 10.1.1.0/24
Router
interface 10-net interface 201-net
10.1.1.4
10.1.1.2
10.1.1.3
Outbound: Translate source pool 10.1.1.0/24 to global pool 192.50.20.0/24
Global Internet
(192.50.20.0/24)
interface 192-net
et.2.3
Translate source pool 10.1.1.0/24 to global pool 201.50.20.0/24
interface create ip 10-net address-netmask 10.1.1.1/24 port et.2.1
interface create ip 192-net address-netmask 192.50.20.0/24 port et.2.2
interface create ip 201-net address-netmask 201.50.20.0/24 port et.2.3
nat set interface 10-net inside
nat set interface 192-net outside
nat set interface 201-net outside