general route statment question.. any help? 1

[geranimo666]

Hi all-

Well I have a new router with certain users in my network that need to get to the web but not others... I know this question is extremely elementary but here goes...

I know I need a static route statement that states my users on my lan 172.16.x.x get to an ISP global address range.. but what about natting? How to I properly write the config line for nattin this particular traffic..

any help would be most appreciated.

geranimo

 

[IllogicallyLogical]

Not knowing your setup, I can give you a basic walkthrough of PAT (overloaded NAT). PAT will enable multiple private IPs to translate to a single Public IP.

Step 1: (Optional) If you have a pool multiple public IPs you want to translate you can create a pool. PAT is capable of translating thousands of private addresses to a single public IP.

Router(config)#ip nat pool geranimo 63.128.54.129 63.128.54.135 netmask 255.255.255.128

Geranimo is the name of the nat pool....it could be whatever name you want. 63.128.54.29 is the start of the nat pool and 63.128.54.135 is the end. 255.255.255.128 is of course the subnet mask. If you are using just one public IP make the starting and ending address the same in the pool.

Step 2: Configure an ACL to define which private IP addresses will be translated.

Router(config)#access-list 1 permit 172.16.0.0 0.0.255.255

Step 3: Now you can choose to either link the ACL to the outside public interface or link the ACL to the nat pool.

(link to outside interface method)
Router(config)#ip nat inside source list 1 interface serial 0/1 overload

(link to nat pool)
Router(config)#ip nat inside source list 1 pool geranimo overload

Step 4: Define the inside interfaces...multiple inside interfaces can be configured (interfaces with private IPs)

Router(config)#interface fa 0/0
Router(config-if)#ip nat inside

Step 5: Define the outside interface (public interface)

Router(config)#interface serial 0/1
Router(config-if)#ip nat outside


This should help get you going.



Joey
A+, Network+, MCP