Can anyone confirm that the PREROUTING chain is absent from the OUTPUT packet path? I wanted to tag my UDP packets with TOS Minimize-Delay so that they'd go in my high-priority traffic shaping queues, but if PREROUTING isn't used in the output path, the packets can't be tagged until after they've been through the shaper. (Isn't the shaper part of "routing decision" in the diagrams?)
The equivalent of PREROUTING chain for locally generated packets would be OUTPUT chain. It exists in filter, nat, and mangle tables. I'd guess what you need is something like:
iptables -t mangle -A OUTPUT -p udp -j TOS --set-tos Minimize-Delay iptables -t mangle -A PREROUTING -p udp -j TOS --set-tos Minimize-Delay
First line would handle locally generated packets, second would handle forwarded packets (it would catch incoming too, but I guess it can be safely ignored in this case).
-- Aleksandar Milivojevic <amilivojevic@xxxxxx> Pollard Banknote Limited Systems Administrator 1499 Buffalo Place Tel: (204) 474-2323 ext 276 Winnipeg, MB R3T 1L7
