Resolution
The P1 refers to phase 1 Internet Security Association and Key Management Protocol (ISAKMP). The notify (in) indicates that this VPN end point received a Delete Notify message, which is the request to delete phase 1 for this tunnel from the remote peer.
If you see this error message while the VPN tunnel fails to come up, gather more IPSec debugs from both VPN end points and look for a more specific error message that would point to where the problem is.
For an explanation of common debug commands used in troubleshooting IPSec issues, refer to IP Security Troubleshooting - Understanding and Using debug Commands.
Product Family
Firewall - PIX 500 series
Routers
