In this configuration, 192.168.100.255 is an SMTP Server that we would like to publish on internet with public IP address 221.200.200.51 and open port tcp/25.
STATIC NAT:
(config)# access-list outside_access_in extended permit tcp any host 192.168.100.235 eq smtp
(config)# access-group outside_access_in interface outside
(config)# object network srv_192.168.100.235
(config)# host 192.168.100.235
(config)# nat (inside,outside) static 221.200.200.51 service tcp 25 25
STATIC NAT BI-DIRECTIONAL:
$2.75 per month(config)# access-list outside_access_in extended permit tcp any host 192.168.100.235 eq smtp
(config)# access-list outside_access_in in interface outside
(config)# access-list inside_access_out extended permit tcp 192.168.100.235 255.255.255.0 eq smtp
(config)# access-group inside_access_out in interface inside
(config)# object network srv_192.168.100.235
(config)# host 192.168.100.235
(config)# object network public_ip_51
(config)# host 221.200.200.51
(config)# nat (inside,outside) source static srv_192.168.100.235 public_ip_51
