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port forward on asa5510

On of our customers is asking us to set up a port forward from port 587 to port 26 because his client uses verizion for their mail server.

What is the best way to set this up?

Cisco Employee

Re: port forward on asa5510

Here is an example:

Mail server:

NATed (public ip of mail server):

static (inside,outside) tcp 587 26 netmask

On the outside ACL, you would need to permit tcp any host eq 587

In regards to port forwarding to port 26, not sure whether it is a typo because mail is normally on port 25, but you can always change it accordingly.

Hope that helps.

Cisco Employee

Re: port forward on asa5510


Are you trying to do the port translation for the server which is on the

outside interface of your network? i.e. your client will send data to port

587 and when it exits your network, it should be converted to port 25? Or is

the other way around i.e. Verizon uses port 587 and your client wants to see

it as port 25?

Case 1: Client sends it to 587 and Verizon wants it on port 25

Static (outside,inside) tcp 587 25 netmask

Case 2: Client sends it to 25, but Verizon is using port 587

Static (outside,inside) tcp 25 587 netmask

Hope this helps.