On 25 Jan 2013 17:23, "Michael Richardson" wrote: > It also seems that there is no control to keep dnsmasq from answering > on my ge00. I guess some trojans try to use me for DOS amplication by > asking for isc.org continuously? There is. Although dnsmasq listens on 0.0.0.0:53 and :::53 it is not responding on ge00. Thanks to list notinterface ge00 in /etc/config/dhcp This means that port 53 is open, but DNS is not accessible from ge00, see: solt@mkslnx004:~$ nmap -sV -p 53 A.B.C.D Starting Nmap 5.21 ( http://nmap.org ) at 2013-01-25 18:55 CET Nmap scan report for XXXXX (A.B.C.D) Host is up (0.018s latency). PORT STATE SERVICE VERSION 53/tcp open tcpwrapped Service detection performed. Please report any incorrect results at http://nmap.org/submit/ . Nmap done: 1 IP address (1 host up) scanned in 0.75 seconds solt@mkslnx004:~$ nslookup kernel.org A.B.C.D ;; connection timed out; no servers could be reached If you want to close that down you could be drop all on ge00 by: iptables -I zone_wan -j DROP or just filter 53. Regards, Maciej