PAT and NAT concept

[prince.p]

Hi Friends,

I am having some doubt in PAT and NAT concept . in our office we are using one public ip address and 90 LAN address. all the LAN can access internet with the help of single public ip address. in this concept, Are we using PAT in our network or any type of NAT is using here? . if we are using PAT means weather I can configure Static PAT ie particular Wan port number to map to  particular Lan port number with out lan ip address. kindy help me.

[Mark Malone]

Hi
Your using what's called NAT overload or PAT here is an example link below and what exactly it does and how , you could also configure specific hardcoded nat translations too if required , NAT overload works in a dynamic function

http://www.firewall.cx/cisco-technical-knowledgebase/cisco-routers/260-cisco-router-nat-overload.html

[prince.p]

weather i can NAT particular external wan port number ie like 5000 to map
internal system port number like 3389 with out mentioning lan ip address.
ie only i want to map wan port to Lan port.

[Mark Malone]

you can change the port number as it moves through for security to obscure it but you need to have the ip addresses or it wont know what to map too

This example shows the configuration for static PAT:

ip nat inside source static tcp 10.11.1.1 1 210.11.1.1 101 
ip nat inside source static tcp 10.11.1.1 2 210.11.1.1 201 
ip nat inside source static tcp 10.11.1.1 3 210.11.1.1 301 
ip nat inside source static tcp 10.11.1.1 4 210.11.1.1 401 
ip nat inside source static tcp 10.11.1.1 5 210.11.1.1 501 
ip nat inside source static tcp 10.11.1.1 6 210.11.1.1 601 
ip nat inside source static tcp 10.11.1.1 7 210.11.1.1 701 
ip nat inside source static tcp 10.11.1.1 8 210.11.1.1 801 
ip nat inside source static tcp 10.11.1.1 9 210.11.1.1 901 
ip nat inside source static tcp 10.11.1.1 10 210.11.1.1 1001 
ip nat inside source static tcp 10.11.1.1 11 210.11.1.1 1101 
ip nat inside source static tcp 10.11.1.1 12 210.11.1.1 1201 

[prince.p]

can i able to check pat configuration like show pat in cisco router

[Mark Malone · Accepted solution]

pat translations would be included in nat translations with command below , you could use that to see exactly what translations are taking place dynamic or static

xxxxxxxxx#sh ip nat translations
udp 62.221.5.119:4500 208.161.242.176:4500 188.120.92.99:4500 188.120.92.99:4500
udp 62.221.5.119:4500 208.161.242.176:4500 58.33.62.151:4500 52.33.68.151:4500

[prince.p]

thanks a lot.