Cisco 1710 Spezifikationen PDF herunterladen (Seite 41)

2-11

Cisco 1710 Security Router Software Configuration Guide

78-12696-01

Chapter 2 Cisco 1710 Security Router Configuration

Configuring Network Address Translation

Configuration Example

In this example, we want NAT to allow certain devices on the inside to originate

communication with devices on the outside by translating their internal addresses

to valid outside addresses or a pool of addresses. The pool in this example is

defined as the range of addresses 172.16.10.1 through 172.16.10.63.

In order to accomplish this translation, we need to use dynamic NAT. With

dynamic NAT, the translation table in the router is initially empty and gets

populated once traffic that needs to be translated passes through the router. (This

is opposed to static NAT, in which a translation is statically configured and is

placed in the translation table without the need for any traffic.)

In this example, we can configure NAT to translate each inside device address to

a unique valid outside address, or to translate each inside device address to the

same valid outside address. The second method is known as overloading. An

example of how to configure each method is given here.

To begin, configure the Fast Ethernet interface with an IP address and as a “NAT

inside” interface.

interface FastEthernet 0

ip address 10.10.10.1 255.255.255.0

ip nat inside

Then configure the Ethernet interface with an IP address and as a “NAT outside”

interface.

interface Ethernet 0

ip address 172.16.10.64 255.255.255.0

ip nat outside

To handle the case in which each inside address is translated to its own unique

outside address, define a NAT pool named “no-overload” with a range of

addresses from 172.16.10.0 to 172.16.10.63

ip nat pool no-overload 172.16.10.0 172.16.10.63 prefix 24

Define access list 7 to permit packets with source addresses ranging from

10.10.10.0 through 10.10.10.31 and from 10.10.20.0 through 10.10.20.31.

access-list 7 permit 10.10.10.0 0.0.0.31

access-list 7 permit 10.10.20.0 0.0.0.31

1 2 ... 36 37 38 39 40 41 42 43 44 45 46 ... 87 88

Keine Kommentare

Cisco 1710 Spezifikationen Seite 41