I'm trying to set up outside access for a couple machines here using VNC. They can both be accessed locally, and I was able to configure the first one for external access, but when trying to configure the second I get the error:

The server address configuration overlaps with an existing translation rule.

I would like to use the same domain name to connect to, but differentiate based on port number. So mydomain.com:5902 would go to one PC and mydomain.com:5903 would go to another. I'm using a Cisco ASA 5510 with ASDM 6.4.

I set the DNS record up on our name server, and it works for the first one, but I keep getting the conflict error when trying to set the second one up through the "Public Servers" option in ASDM. Is there something I am doing wrong?

enter image description here

  • 1
    Static NAT is 1:1 -- Read up on PAT cisco.com/c/en/us/td/docs/security/asa/asa82/configuration/… Jun 16, 2015 at 15:24
  • Can you post the relevant parts of your config?
    – Ron Trunk
    Jun 16, 2015 at 18:01
  • Did any answer help you? if so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer.
    – Ron Maupin
    Aug 11, 2017 at 4:41

1 Answer 1


You need to create a static NAT rule that translates your internal hosts to their external equivalents. Use the following commands (add in your public IP):

static (inside,outside) TCP *ExternalIP* 5902 5902 netmask
static (inside,outside) TCP *ExternalIP* 5903 5903 netmask

And then create the appropriate ACL rules to allow this traffic.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.