I started seeing a ton of messages in my IDS (Snort) showing inbound ICMP Destination host unreachable message. I'm on a net that uses private IPs. The source IP is always one of two addresses. One is a private IP address that's not on my subnet, the other is a public IP address that's not part of my public address space, but that I believe is part of my ISP's network. The destination address is always the address of my workstation.

I've disable the adapter and unplugged it from the network while I attempt to figure out what's going on. Any suggestions would be greatly appreciated.