Translate Random TCP port to a single TCP port using IOS router

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Jul 30th, 2010
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My name is Zulkarnain Kamaludin from Kuala Lumpur, Malaysia. I have setup as follows: Users from outside networks need to communicate with inside host. The inside host only open a single TCP port let says port 15000 and only can talk to the TCP port 15000. The problem is the users outside is opening randomly TCP port and I need to translate this random ports to TCP port 15000. Can it be achieve? Thanks in advance.


Zulkarnain Kamaludin

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waltermavely Fri, 07/30/2010 - 09:04
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         Let me brief your question there is one server inside you network which is running service with tcp port 15000 , Outside users want to

access this service from there workstation. I hope this is your requirement  then configure the static nat your device

If it is firewall you can use this command static ( inside,outside) xxx(outsideip) xxxx(serverip) -the configure the access-rule in the outside interface

all tcp port 15000

if it is router use this ip nat inside source static serverip outside(transating ip)


under the inside interface

ip nat inside

under the outside interface

ip nat outside

i hope this your requirement if not please clarify youre requirement


Nagaraja Thanthry Fri, 07/30/2010 - 09:22
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  • Cisco Employee,


Unfortunately, it does not look like an IOS router can do what you are looking for. You could try a firewall (ASA) with 8.3 code where there is a workaround to acheive this.

Hope this helps.




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