I have an IPSEC VPN set up on an ASA 5520. I have a few clients on it for testing purposes. All clients are working fine, except one that I keep receiving this message for:
IPSEC: Received an ESP packet (SPI= 0xA71AC130, sequence number= 0xB2C57) from (his external IP)(user= XXX) to (our ext. IP) that failed authentication.
I get the error in ~20 second intervals. He is passing traffic and not noticiing any problems, but this error is annoying. Any idea what is going on?