Our ISP has installed a new router in one of our remote offices. Even though the IP address has not changed, we are receiving errors when the VPN tries to connect our remote SSG5 to our SSG20. The event log has the following errors in it:
Rejected an IKE packet on ethernet0/0 from REMOTEIPGATEWAY:500 to SSG20PUBLICIP:500 with cookies (NOMNOMNOMcookies) and 0000000000000000 because an initial Phase 1 packet arrived from an unrecognized peer gateway.
IKE<REMOTEIP> Phase 1: Retransmission limit has been reached.
The new router is a Cisco model. Troubleshooting steps taken include reboots of all relavent equipment, changing gateway settings on SSG20 to Agressive mode.