What I want to do is say that for all UDP connections on interface ppp0 that have a destination port of
53, change that destination port to 1053.
I am attempting to change the destination port of UDP packets for VPN clients connected via PPTP on Ubuntu.
suggests that this can be done using NAT at the
--to-destination option, for example:
iptables -t nat -A OUTPUT -p udp --dport 53 -j DNAT --to-destination x.x.x.x:1053
This does work but it changes the port for ALL packets going out on port
53 but I only want to change the port for some of my VPN clients who are connected on interface
ppp0-255 and IP range
I have tried adding the source into the statement, for example:
iptables -t nat -A OUTPUT -s 192.168.0.10 -p udp --dport 53 -j DNAT --to-destination x.x.x.x:1053
This however does not appear to work and the VPN connections still go through to port