topic Re: NAT Rule Causing Internet Connectivity Issues in Network Security

NAT Rule Causing Internet Connectivity Issues

TedEdward — Tue, 22 Mar 2022 11:25:14 GMT

Hi,

I have a NAT rule on our FPR-1010 running ASA to allow incoming traffic on outside interface on port 65020. The rule works and have required access externally.

The problem I have is the internal server that it is accessing has internet connectivity issues.

For example when I open Chrome on it I can't get to https://www.grc.com but can get to other sites. This is causing problems for the software running on the server.

This is the NAT rule.

(Inside) to (Outside) source static SERVER interface service any 65020Source inactive.

Does anyone know what the issue could be please?

Thanks

Re: NAT Rule Causing Internet Connectivity Issues

balaji.bandi — Tue, 22 Mar 2022 12:05:23 GMT

For example when I open Chrome on it I can't get to https://www.grc.com but can get to other sites. This is causing problems for the software running on the server.

is this from inside network or outside network ?

what you mean other site ? they also NATted ?

from Lan are you able to access that site ? what port ?

Re: NAT Rule Causing Internet Connectivity Issues

MHM Cisco World — Tue, 22 Mar 2022 13:24:04 GMT

(Inside) to (Outside) source static SERVER interface service any 65020
the source Port is OK
the destination Port is Wrong ...
service any 65020 at the end of NAT is wrong, this for destination port, i.e.
costumer in outside will ask specific port that NAT to 65020, here you make all destination port NAT to 65020...!!!
please change it to be
Inside-FW-Outside
the client in outside will use port for example 5000 will nat to 65020 which use by Server in Inside.
the client in outside will use port 65020 will nat to 65020 which use by server in inside.

I think you misunderstood the Service and assign ANY as it the source port.