Hi Sluggers, I have a strange requirement to redirect UDP packets sent to 255.255.255.255, forwarding them to another machine in a remote network... yes, this is borked - there is an application sending data to 255.255.255.255, not multicast or unicast, but broadcasting UPD packets, and I'm in no position to change or question this strangeness..
Anyway, so this should be quite simple - run a DNAT rule changing the destination address in the pre-routing chain of the nat table ie iptables -t nat -I PREROUTING -d 255.255.255.255 -j DNAT --to-dest 192.168.x.y however this doesn't work.. it doesn't even work if I specify the source of the broadcasts rather than the destination, eg iptables -t nat -I PREROUTING -s 192.168.y.z -j DNAT --to-dest 192.168.x.y and specifying input and output interfaces doesn't help either I have ip_forwarding enabled, and if I change this rule to be from my workstation, then I can see that it works - ie iptables -t nat -I PREROUTING -s my.ip.add.ress -j DNAT --to-dest 192.168.x.y and then ping the host with the iptables rules, I can see with tcpdump that my pings go back out and onto the remote network.. so, I know iptables is working, and I know forwarding is working, I just can't make a rule that effects packets sent to 255.255.255.255 Has anyone got any clues as to why broadcasts aren't being matched and DNAT'd? Thanks -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
