NAT

Auvii

I have been practicing several different network builds while reading and recently got to NAT. I read over the exam "requirements" I didn't see anything, at least explicitly, regarding NAT and setting up a network using NAT pools. Is this something that I should focus on or rather just know its basics?

Netstudent

I would focus in on it because no matter where you work, or what you do in the IT field, you will always have to be aware of NAT characteristics. So more importantly you need to know NAT for the real world. Almost all shops have internal services than need to be accessed from the outside. Secondly, it is part of the CCNA curriculum. So yes know it!

Auvii

Ok that works. To me next question then heh.....

I have been trying to create a NAT pool and network using 2 1700's, 3550 switch, and 2 host pc's. I was thinking I could have one router act as if it is the "internet" while the other router gave the NAT pool. The NAT router in this set up had the two host pc's connected to the 3550 with no vlans or anything, just normal L2 switching. SO basically I cant seem to get it to work as planned. My biggest problem is that I cant quite grasp the NAT topic I suppose. Though I understand its purpose and goal I am uncertain of the configuration requirements. Does the router act as the DHCP "server" in this situation?

If someone could point to a thorough explanation or even throw some basic info here that would be great. I currently have the Cisco books and Lammle's newest book and I feel both do not give the same attention it gives to other topics within them.

Maybe its me, any tips would be great, thanks.

Netstudent

Try looking around the cisco whitepapers or the DOCs for extra information. Basically your private subnets will be an "ip nat inside" interface and the public subnets will be the "ip nat outside". You setup a natpool by doing

ip nat pool Mypool 200.63.63.1 200.63.63.3 netmask 255.255.255.0
ip nat inside source list 1 pool Mypool
access-list 1 permit ip 192.168.1.0 0.0.0.255

http://www.cisco.com/warp/public/556/12.html


The router will act as a DHCP only if you setup ip dhcp parameters.

Auvii

Ok I will play around with those commands a bit and check out those docs. Thanks.