We recently got an abuse report of an IP address in our net range. However, that IP address isn't in use in our networks and the covering network is null routed, so no return traffic is possible. We have external BGP monitoring, so unless something very tricky is going on, we don't have part of our prefix hijacked. I assume the source address was spoofed, but this leads to my question. Since the person that submitted the report didn't mention a high packet rate (it was on ssh port 22), it doesn't look like some sort of SYN attack, but any OS fingerprinting or doorknob twisting wouldn't be useful from the attacker if the traffic doesn't return to them, so what gives? BTW, we are in the ARIN region, the report came out of the RIPE region. ---- Matthew Huff | 1 Manhattanville Rd Director of Operations | Purchase, NY 10577 OTA Management LLC | Phone: 914-460-4039 aim: matthewbhuff | Fax: 914-694-5669