I'm having some trouble with DNAT, on WNDR3700v2 (LEDE build, r1298)
I've set the firewall to redirect some ports to a Debian machine on my local network, which have itself a firewall which distinguates "local" packets (basically 192.168.x.y) and "foreign" ones (everything else). Amongst redirected ports are smtp-related ports (25/465/587), and torrent port (custom port, 12345)
The logs on the Debian machine shows that some foreign packets seem to originate from my router.
I unfortunately can't reproduce this by hand, as this behaviour seems to be only triggered when a lot of packets arrive : I've seen it for Torrent connections (torrent clients are not reputed for their niceness), as well as spamming "relay" attempts.
I'm not sure this is related to hnyman's build, as I think I had the same behaviour with an old build from arokh.
It might also be WNDR3700-specific, or just a faulty unit on my side.
Did anyone encountered this ? Any ideas to investigate further ?