Proftpd MLSD issue on centos 6

Yesterday I updated one of centos 6 servers and it also updated proftp from virtualmin repo. Proftp couldnt start after the update because of unknown VRootEngine directives, I fixed this by copying proftpd.conf.rpmnew to proftpd.conf and proftpd started working.

Now it appears that this new version of proftpd provided by Virtualmin is not compatible with centos 6 and users connections are timed out at MLSD ftp command. (No firewall on client or server side). I tried this link but it didn't work :

there is no such module in centos 6 kernel ip_conntrack_ftp

I temporarily fixed this issue by downgrading proftp to v1.3.3 epel.

Here is the exact error that I see when using proftpd 1.3.5d-2.el6 virtualmin :

Command: MLSD
Error: Connection timed out
Error: Failed to retrieve directory listing

however no errors happen when using proftpd 1.3.3g-10.el6 epel :

Command: MLSD
Response: 150 Opening ASCII mode data connection for MLSD
Response: 226 Transfer complete

both using /etc/proftpd.conf provided by 1.3.5d-2.el6 virtualmin package.



Hmm, can you try loading the module named "nf_conntrack_ftp"?

After doing that, does the new ProFTPd package work for you?

Mostafa's picture
Submitted by Mostafa on Wed, 05/24/2017 - 09:17

The module is already loaded:

[root@sv ~]# lsmod | grep -i nf_conntrack_ftp
nf_conntrack_ftp       12049  1 nf_nat_ftp
nf_conntrack           79537  11 xt_connlimit,nf_conntrack_ipv6,xt_state,nf_nat_ftp,nf_conntrack_ftp,nf_conntrack_netlink,xt_conntrack,ipt_MASQUERADE,iptable_nat,nf_nat,nf_conntrack_ipv4

and it does not work yet, still the same MLSD connection timeout issue when using proftpd 1.3.5d-2.el6 virtualmin package.