turn off firewall or unlock packet forwarding

OpenSuSE

$ /sbin/SuSEfirewall2 off

enable forwarding:

$ echo 1 > /proc/sys/net/ipv4/ip_forward

firewall rules to block dns traffic:

$ iptables -A FORWARD -p tcp --dport 53 -j DROP
$ iptables -A FORWARD -p udp --dport 53 -j DROP

TODO:

turn off ARP reply in server to prevent duplicate mac entry in target ARP table.