We force all users to register against our DNS name, then use IP Tables to reject REGISTER methods coming against our IP address: iptables -I INPUT -j DROP -p udp --dport 5060 -m string --string "REGISTER sip:a.c.d.e SIP" --algo bm iptables -I INPUT -j DROP -p udp --dport 5060 -m string --string "REGISTER sip:a.c.d.e:5060 SIP" --algo bm Where a.b.c.d is your public IP address. This will stop responses to initial SIPVicious explorations also, which means you don't get on their list in the first place and save a whole lot of useless UDP blasts which come from their brute force attacks. -- View this message in context: http://freeswitch-users.2379917.n2.nabble.com/SIP-attacks-from-188-161-101-7... Sent from the freeswitch-users mailing list archive at Nabble.com.