Is port 21 active?

Question

I have recently installed sftp (secure shell ftp) into proftpd. Knowing that the default port for sftp is 22, I have also changed the port value from 23 to 22 in /etc/proftpd.sftp.conf. So I expect it only to work through this port. Yet when I telnet port 21, it returns:

220 ProFTPD 1.3.5 Server ready.

Does that mean port 21 is active? If so, how can I close it? I am running csf as firewall and have only added port 22 for ftp in TCP_IN and TCP_OUT.

BTW, my server uses centos 6.5 and Directadmin panel.

Any ideas?

Thanks.

[Administration panels are off topic](http://serverfault.com/help/on-topic). [Even the presence of an administration panel on a system,](http://meta.serverfault.com/q/6538/118258) because they [take over the systems in strange and non-standard ways, making it difficult or even impossible for actual system administrators to manage the servers normally](http://meta.serverfault.com/a/3924/118258), and tend to indicate low-quality questions from *users* with insufficient knowledge for this site. — HopelessN00b, Apr 09 '15 at 15:45

score 1 · Answer 1 · answered Aug 16 '14 at 11:25

1

You don't say where you did the telnet from, but assuming it's off the server, then yes, it does.
iptables -I INPUT 1 -p tcp --dport 21 -j REJECT

answered Aug 16 '14 at 11:25

MadHatter

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Thanks. By "off the server" you mean "from my own server? – developer Aug 16 '14 at 12:35
No, I mean "from any client other than the server in question itself". – MadHatter Aug 16 '14 at 14:09
No, I telnet from my own server. Does it mean port 21 is closed? – developer Aug 16 '14 at 15:21
1

No, it just means you can't tell; that's not a very good experiment. Try from off the server. – MadHatter Aug 16 '14 at 20:57

Is port 21 active?

1 Answers1