Quick port question, please please help

[ianbla]

Can I have an ip address e.g. 111.111.111.111 translated to my internal IP of 222.222.222.222 81.

What I want to do is let people access the website held on port 81 but not have to open their firewall to 81, they should be able to get to it using standard port 80.

I hope somebody can help.

 

[gbiello]

I think this is how it works:

access-list inbound permit tcp any host 1.2.3.4 eq 80
static (inside,outside) tcp host 1.2.3.4 80 192.168.1.100 81 netmask 255.255.255.255 0 0

in your case:
access-list inbound permit tcp any host 111.111.111.111 eq 80
static (inside,outside) tcp host 111.111.111.111 80 222.222.222.222 81 netmask 255.255.255.255 0 0

This would take an inbound request on port 80 and map it to a private IP on port 81.

-gbiello