How to do NAT in 1603 router

Posted on 2003-03-06
Medium Priority
Last Modified: 2010-05-18
I am new to cisco. i am trying to configure 1603 router. I did it . i can access the internet.but the ISP is giving 2 fixed IP i wants to do natinfg in the router. Could u pls explain how to NAT in router. my internal network is  and the ISP given IP is astarting in 213.x.x.x .
Waiting for your valuable reply
Question by:jayan_k
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions

Accepted Solution

pratigan earned 200 total points
ID: 8080352
Hello Jayan,

If your router uses NAT, it should be replacing the source IP of your private machines (192.x.x.x) with the public IP of the router (dynamically assigned by ISP) then sending it out.
The router fights invasion in a couple of different ways:

1) Prevents unknown computers from accessing the network ports on your PC, by hiding your actual PC's IP address. This is called Network Address Translation (NAT), and is a simple but effective block for preventing outside-in penetration. Basically, all a cracker could see would be your router's IP address, which doesn't have any programmability that he can attack.

2) An IP address filter, that sets up a hard block against certain IP addresses you specify in the router. This would be useful say, if you were China and wanted to block all communications with Google. It can also be used to prevent your teenagers from getting to Playboy.com, but most of these routers are a pain to configure for blocking, and some have a limit on the number of IP addresses they can filter.

Depending upon what you want to do, I would probably suggest that the NAT features are an effective way to prevent intrusion, and that if you needed to provide outbound security for web sites that you use something like NetNanny or other filtering program. These ARE updated frequently by their authors to contain all the new sites, and are a whole lot easier than trying to use the router admin program to add 50 sites a day...
Here are a few informational sites that may also be helpful.

Good Luck !!

LVL 32

Expert Comment

ID: 10122978
pratiganNo comment has been added lately, so it's time to clean up this TA.
I will leave a recommendation in the Cleanup topic area that this question is:

Answered by pratigan

Please leave any comments here within the next seven days.


EE Cleanup Volunteer

Featured Post

On Demand Webinar: Networking for the Cloud Era

Did you know SD-WANs can improve network connectivity? Check out this webinar to learn how an SD-WAN simplified, one-click tool can help you migrate and manage data in the cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Ever notice how you can't use a new drive in Windows without having Windows assigning a Disk Signature?  Ever have a signature collision problem (especially with Virtual Machines?)  This article is intended to help you understand what's going on and…
Concerto Cloud Services, a provider of fully managed private, public and hybrid cloud solutions, announced today it was named to the 20 Coolest Cloud Infrastructure Vendors Of The 2017 Cloud  (http://www.concertocloud.com/about/in-the-news/2017/02/0…
This tutorial will walk an individual through the process of installing the necessary services and then configuring a Windows Server 2012 system as an iSCSI target. To install the necessary roles, go to Server Manager, and select Add Roles and Featu…
This Micro Tutorial will teach you how to reformat your flash drive. Sometimes your flash drive may have issues carrying files so this will completely restore it to manufacturing settings. Make sure to backup all files before reformatting. This w…
Suggested Courses

762 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question