
Table of Contents
iii
Configuring Network Address Translation . . . . . 55
Overview of NAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Viewing NAT Global Settings
and Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Viewing NAT Rules and Rule Statistics . . . . . . . . . . . . . . . . . .60
Viewing Current NAT Translations . . . . . . . . . . . . . . . . . . . . . .61
Adding NAT Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
The NAPT rule: Translating between private
and public IP addresses . . . . . . . . . . . . . . . . . . . . . . . . .64
The RDR rule: Allowing external access
to a LAN computer . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
The Basic rule: Performing 1:1 translations . . . . . . . . . .71
The Filter rule: Configuring a BASIC rule
with additional criteria . . . . . . . . . . . . . . . . . . . . . . . . . . .73
The Bimap rule: Performing two-way translations . . . . .75
The Pass rule: Allowing specific addresses to pass through
untranslated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77
Configuring DNS Server Addresses . . . . . . . . . . 79
About DNS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79
Assigning DNS Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . .79
Configuring DNS Relay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80
Configuring IP Routes . . . . . . . . . . . . . . . . . . . . . 83
Overview of IP Routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .83
IP routing versus telephone switching . . . . . . . . . . . . . .83
Hops and gateways . . . . . . . . . . . . . . . . . . . . . . . . . . . .84
Using IP routes to define default gateways . . . . . . . . . .85
Do I need to define IP routes? . . . . . . . . . . . . . . . . . . . .85
Viewing the IP Routing Table . . . . . . . . . . . . . . . . . . . . . . . . . .86
Adding IP Routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88
Configuring the Routing Information Protocol . 91
RIP Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91
When should you configure RIP? . . . . . . . . . . . . . . . . . .92
Configuring the ADSL Barricade's Interfaces with RIP . . . . . . .92
Viewing RIP Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .96