%Port 4500 is being used by system

[szabolcs.verebelyi]

Hello,

I was trying to add a static NAT entry for a Cisco ASR 1002-x and it was not possible because I got error: %Port 4500 is being used by system. 

ip nat inside source static udp 10.0.x.x 4500 193.x.x.x 4500 extendable

%Port 4500 is being used by system

How can I solve this? I tried remove PAT and reload and add NAT but it wasn't help.

Do you have any idea why is reserved this port by the router?

Is there any chance to turn off this feature?

Thx

[balaji.bandi]

what is this device and what code running ?

how does your config looks like : ( do you have any ipsec running on the router already) - check that.

4500, udp, ipsec, IPSec (VPN tunneling)

or may be bug: check below :

https://community.cisco.com/t5/switching/quot-nat-port-lt-gt-is-being-used-by-system-quot-on-cisco/td-p/2890534

[szabolcs.verebelyi]

Hello,

I have try this topic that you mentioned, but not solved my problem.

The device is ASR1002-x and tried many version of the software even the latest 17.7.1a.

I didn't configure IPsec on router. How can I check if it is running?

Thanks

Szabolcs

[balaji.bandi · Accepted solution]

Can you post  : show run  from the router for us to understand the issue here.

[Deepak Kumar · Accepted solution]

Hello,

Kindly export the running configuration and attached to the post so we can check your configuration too.