This issue occurs due to the presence of Cisco bug ID CSCsd08170.
This problem occurs when there is already an existing xlate for the interface IP address on port 500.
In order to display the port translations on port 500, issue the show xlate global | inc 500 command.
In order to resolve this issue, perform one of these steps:
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: