> -----Original Message----- > From: Bruno de Paula Larini [mailto:bruno.larini@xxxxxxxxxxxxxx] > Sent: woensdag 15 augustus 2018 19:11 > To: Vink, Ronald; 'netfilter@xxxxxxxxxxxxxxx' > Subject: Re: cant get ftp forwarding working > > Em 14/08/2018 09:37, Vink, Ronald escreveu: > > I want to forward ftp traffic from outside to a server in a local network. > > I am using active ftp connection. > > It is working with a 3.5.4 kernel system, but not on a newer 4.9.59 > > > > eth0 eth1 > > |--------------------------| local |-------------------------------------------- > | company |----------------------------| > > |proftpd 10.10.203.10 |------------|10.10.203.150 Gateway 10.141.12.21|---- > -VPN----|10.101.34.25 ftp client | > > |--------------------------| network |-------------------------------------------- > | |----------------------------| > > > > Working rules in 3.5.4 kernel system : > > iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE > > iptables -t nat -A PREROUTING -p tcp -i eth1 --dport 21 -j DNAT --to- > destination 10.10.203.10:21 > > > > I have tried with all sorts of different rules, but have not been able to make > it work. > > Tried to google it, but found no working example. > > Any hints? > > > > Ronald > > > > > Hello Vink. > I had the same issue in a very specific scenario regarding FTP NAT. My > rules were working on kernel 4.6, stopped working on 4.7 and started > working again from version 4.13. > It was the very same ruleset, nothing was changed. At the time I tested > them on 3 different distros and all had the same behaviour. I still > don't know what happened in between those versions, even the changelog > doesn't say much. > So you may want to try upgrading your kernel, if possible. > > My original post is here: > https://www.spinics.net/lists/netfilter/msg57478.html > > Good luck! With kernel 4.18.1 and echo 1 > /proc/sys/net/netfilter/nf_conntrack_helper it works
