cisco 2600 v11.3 Dynamic nat How to?
Posted on 2008-11-07
I have ver 11.3 software in a cisco 2611
I am trying to use it to do NAT. I found this here:
//I assume you have interface e0 with valid ip address
Router(config-if)#ip nat inside //this is to your trusted network - LAN
//I assume you have interface s0 with valid ip address
Router(config-if)#ip nat out //this is to untrusted network - WAN
//Here we go - static addresses for your servers. I assume you want people to find them
//without calling you every time you make changes in your network
Router(config)#ip nat inside source static 192.xxx.xxx.xxx 207.xxx.xxx.xxx //Webserver
Router(config)#ip nat inside source static 192.xxx.xxx.xxx 207.xxx.xxx.xxx //Email
Router(config)#ip nat inside source static 192.xxx.xxx.xxx 207.xxx.xxx.xxx //DNS
Now if you want your workstation to have static IP, it is totally fine. (Use above statements for it)
But in case you want ~4000 (theoretically) workstations to use single public ip address, you might consider using PAT translations:
Router(config)#access-list 1 permit 192.xxx.xxx.xxx 0.0.0.255
Router(config)#ip nat inside source list 1 interface serial 0 overload
Just specify the right pool, excluding your statically assigned IP addresses.
Hope this helps
But I get stuck at the part "IP NAT INSIDE SOURCE STATIC... it flags the word "static" as being invalid. I suspect it may be because of the firmware version.
I also use DHCP inside the lan. so how would this set of commands dynamically NAT? Is that possible?
I am a total newbie but very tenacious so please be gentle.