Why is only 32768 bytes downloaded?

Question

linux

Hello.
There is a server on ubuntu, pure-ftpd is configured on it.
The matter is that for some reason this server gives only 32.768 bytes of files. Tritely I try to pull out a text document from it - 32768 bytes are downloaded, and then filezilla breaks the connection due to inactivity. Moreover, such tricks are not only over FTP, the same situation is happening with sftp.

syslog

[email protected]:~# tail -n 100 /var/log/syslog
Jul 8 16:15:41 vm667364 pure-ftpd[22481]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:16:10 vm667364 pure-ftpd[22481]: ([email protected]) [INFO] Logout.
Jul 8 16:16:14 vm667364 pure-ftpd[22483]: ([email protected]) [INFO] New connection from IP
Jul 8 16:16:14 vm667364 pure-ftpd[22483]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:16:21 vm667364 pure-ftpd[22485]: ([email protected]) [INFO] New connection from IP
Jul 8 16:16:22 vm667364 pure-ftpd[22485]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:16:45 vm667364 pure-ftpd[22487]: ([email protected]) [INFO] New connection from IP
Jul 8 16:16:46 vm667364 pure-ftpd[22487]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:17:01 vm667364 CRON[22490]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Jul 8 16:17:16 vm667364 pure-ftpd[22492]: ([email protected]) [INFO] New connection from IP
Jul 8 16:17:16 vm667364 pure-ftpd[22492]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:18:08 vm667364 pure-ftpd[22485]: ([email protected]) [INFO] Logout.
Jul 8 16:18:08 vm667364 pure-ftpd[22494]: ([email protected]) [INFO] New connection from IP
Jul 8 16:18:08 vm667364 pure-ftpd[22494]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:19:12 vm667364 pure-ftpd[22496]: ([email protected]) [INFO] New connection from IP
Jul 8 16:19:12 vm667364 pure-ftpd[22496]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:20:01 vm667364 pure-ftpd[22494]: ([email protected]) [INFO] Logout.
Jul 8 16:20:01 vm667364 pure-ftpd[22498]: ([email protected]) [INFO] New connection from IP
Jul 8 16:20:02 vm667364 pure-ftpd[22498]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:20:06 vm667364 pure-ftpd[22496]: ([email protected]) [INFO] Logout.
Jul 8 16:20:06 vm667364 pure-ftpd[22500]: ([email protected]) [INFO] New connection from IP
Jul 8 16:20:06 vm667364 pure-ftpd[22500]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:20:31 vm667364 pure-ftpd[22498]: ([email protected]) [INFO] Logout.
Jul 8 16:20:31 vm667364 pure-ftpd[22504]: ([email protected]) [INFO] New connection from IP
Jul 8 16:20:31 vm667364 pure-ftpd[22504]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:20:33 vm667364 pure-ftpd[22506]: ([email protected]) [INFO] New connection from IP
Jul 8 16:20:34 vm667364 pure-ftpd[22506]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:20:54 vm667364 pure-ftpd[22504]: ([email protected]) [INFO] Logout.
Jul 8 16:20:54 vm667364 pure-ftpd[22508]: ([email protected]) [INFO] New connection from IP
Jul 8 16:20:54 vm667364 pure-ftpd[22508]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:20:57 vm667364 pure-ftpd[22506]: ([email protected]) [INFO] Logout.
Jul 8 16:20:57 vm667364 pure-ftpd[22510]: ([email protected]) [INFO] New connection from IP
Jul 8 16:20:58 vm667364 pure-ftpd[22510]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:21:08 vm667364 pure-ftpd[22512]: ([email protected]) [INFO] New connection from IP
Jul 8 16:21:08 vm667364 pure-ftpd[22512]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:21:11 vm667364 pure-ftpd[22508]: ([email protected]) [INFO] Logout.
Jul 8 16:21:12 vm667364 pure-ftpd[22514]: ([email protected]) [INFO] New connection from IP
Jul 8 16:21:12 vm667364 pure-ftpd[22514]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:22:00 vm667364 pure-ftpd[22510]: ([email protected]) [INFO] Logout.
Jul 8 16:22:13 vm667364 pure-ftpd[22516]: ([email protected]) [INFO] New connection from IP
Jul 8 16:22:14 vm667364 pure-ftpd[22516]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:26:10 vm667364 pure-ftpd[22451]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//MYFILE.txt downloaded (5154282 bytes, 5.59KB/sec)
Jul 8 16:26:10 vm667364 pure-ftpd[22451]: ([email protected]) [INFO] Logout.
Jul 8 16:26:22 vm667364 systemd[1]: Started Session 587 of user root.
Jul 8 16:26:34 vm667364 pure-ftpd[22453]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//MYFILE.txt downloaded (3292141 bytes, 3.57KB/sec)
Jul 8 16:26:34 vm667364 pure-ftpd[22453]: ([email protected]) [INFO] Logout.
Jul 8 16:27:13 vm667364 pure-ftpd[22455]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//MYFILE.txt downloaded (1729393 bytes, 1.88KB/sec)
Jul 8 16:27:13 vm667364 pure-ftpd[22455]: ([email protected]) [INFO] Logout.
Jul 8 16:27:33 vm667364 systemd[1]: Reloading.
Jul 8 16:27:34 vm667364 systemd[1]: message repeated 2 times: [ Reloading.]
Jul 8 16:27:34 vm667364 systemd[1]: Started Run certbot twice daily.
Jul 8 16:27:38 vm667364 pure-ftpd[22457]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//MYFILE.txt downloaded (1729393 bytes, 1.88KB/sec)
Jul 8 16:27:38 vm667364 pure-ftpd[22457]: ([email protected]) [INFO] Logout.
Jul 8 16:28:10 vm667364 pure-ftpd[22463]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//MYFILE.txt downloaded (2328060 bytes, 2.52KB/sec)
Jul 8 16:28:10 vm667364 pure-ftpd[22463]: ([email protected]) [INFO] Logout.
Jul 8 16:28:19 vm667364 pure-ftpd[22465]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//05 07 2019.rar downloaded (2228224 bytes, 2.42KB/sec)
Jul 8 16:28:19 vm667364 pure-ftpd[22465]: ([email protected]) [INFO] Logout.
Jul 8 16:28:40 vm667364 pure-ftpd[22467]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//05 07 2019.rar downloaded (1835008 bytes, 1.99KB/sec)
Jul 8 16:28:41 vm667364 pure-ftpd[22467]: ([email protected]) [INFO] Logout.
Jul 8 16:29:02 vm667364 pure-ftpd[22469]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//05 07 2019.rar downloaded (2228224 bytes, 2.42KB/sec)
Jul 8 16:29:02 vm667364 pure-ftpd[22469]: ([email protected]) [INFO] Logout.
Jul 8 16:29:10 vm667364 pure-ftpd[22516]: ([email protected]) [INFO] Logout.
Jul 8 16:29:23 vm667364 pure-ftpd[22471]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//05 07 2019.rar downloaded (2228224 bytes, 2.42KB/sec)
Jul 8 16:29:23 vm667364 pure-ftpd[22471]: ([email protected]) [INFO] Logout.
Jul 8 16:29:36 vm667364 pure-ftpd[22514]: ([email protected]) [INFO] Logout.
Jul 8 16:29:36 vm667364 pure-ftpd[23323]: ([email protected]) [INFO] New connection from IP
Jul 8 16:29:36 vm667364 pure-ftpd[23323]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:29:40 vm667364 pure-ftpd[23325]: ([email protected]) [INFO] New connection from IP
Jul 8 16:29:41 vm667364 pure-ftpd[23325]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 16:29:44 vm667364 pure-ftpd[22473]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//05 07 2019.rar downloaded (1441792 bytes, 1.56KB/sec)
Jul 8 16:29:44 vm667364 pure-ftpd[22473]: ([email protected]) [INFO] Logout.
Jul 8 16:29:58 vm667364 pure-ftpd[23323]: ([email protected]) [INFO] Logout.
Jul 8 16:30:00 vm667364 systemd[1]: Started Session 588 of user root.
Jul 8 16:30:06 vm667364 pure-ftpd[22475]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//05 07 2019.rar downloaded (6684672 bytes, 7.25KB/sec)
Jul 8 16:30:06 vm667364 pure-ftpd[22475]: ([email protected]) [INFO] Logout.
Jul 8 16:30:13 vm667364 systemd[1]: Started Session 589 of user root.
Jul 8 16:30:27 vm667364 pure-ftpd[22479]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//05 07 2019.rar downloaded (1703936 bytes, 1.85KB/sec)
Jul 8 16:30:27 vm667364 pure-ftpd[22479]: ([email protected]) [INFO] Logout.
Jul 8 16:30:51 vm667364 systemd[1]: Started Session 590 of user root.
Jul 8 16:31:25 vm667364 pure-ftpd[22483]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//MYFILE.txt downloaded (1153107 bytes, 1.25KB/sec)
Jul 8 16:31:25 vm667364 pure-ftpd[22483]: ([email protected]) [INFO] Logout.
Jul 8 16:31:56 vm667364 pure-ftpd[22487]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//MYFILE.txt downloaded (2340888 bytes, 2.54KB/sec)
Jul 8 16:31:56 vm667364 pure-ftpd[22487]: ([email protected]) [INFO] Logout.
Jul 8 16:31:57 vm667364 systemd[1]: Started Session 591 of user root.
Jul 8 16:33:12 vm667364 pure-ftpd[22492]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//MYFILE.txt downloaded (1729898 bytes, 1.88KB/sec)
Jul 8 16:33:12 vm667364 pure-ftpd[22492]: ([email protected]) [INFO] Logout.
Jul 8 16:35:08 vm667364 pure-ftpd[22500]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//MYFILE.txt downloaded (1628142 bytes, 1.77KB/sec)
Jul 8 16:35:08 vm667364 pure-ftpd[22500]: ([email protected]) [INFO] Logout.
Jul 8 16:36:13 vm667364 pure-ftpd[22512]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//MYFILE.txt downloaded (1933589 bytes, 2.10KB/sec)
Jul 8 16:36:13 vm667364 pure-ftpd[22512]: ([email protected]) [INFO] Logout.
Jul 8 16:39:40 vm667364 systemd[1]: Started Session 592 of user root.
Jul 8 16:44:44 vm667364 systemd[1]: Started Session 593 of user root.
Jul 8 16:44:48 vm667364 pure-ftpd[23325]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//MYFILE.txt downloaded (2560712 bytes, 2.78KB/sec)
Jul 8 16:56:45 vm667364 systemd[1]: Started Session 594 of user root.
Jul 8 16:59:48 vm667364 pure-ftpd[23325]: ([email protected]) [INFO] Timeout - try typing a little faster next time
Jul 8 17:01:55 vm667364 kernel: [1792918.107842] nf_conntrack version 0.5.0 (65536 buckets, 262144 max)
Jul 8 17:03:11 vm667364 pure-ftpd[23690]: ([email protected]) [INFO] New connection from IP
Jul 8 17:03:12 vm667364 pure-ftpd[23690]: ([email protected]) [INFO] USERNAME is now logged in
Jul 8 17:03:20 vm667364 pure-ftpd[23692]: ([email protected]) [INFO] New connection from IP
Jul 8 17:03:20 vm667364 pure-ftpd[23692]: ([email protected]) [INFO] USERNAME is now logged in

Please help, I don't understand how to fix this. Thanks in advance.
UPD. After several attempts, 297kb were downloaded, which means that in theory the problem is not in the size restrictions.

logs

Jul 8 18:00:12 vm667364 pure-ftpd[602]: ([email protected]) [INFO] Timeout - try typing a little faster next time
Jul 8 18:00:19 vm667364 pure-ftpd[604]: ([email protected]) [NOTICE] /home/pubftp/MYFOLDER//MYFILE.txt downloaded (1696011 bytes, 1.84KB/sec)
Jul 8 18:02:03 vm667364 pure-ftpd[614]: ([email protected]) [INFO] New connection from IP

Oh yes, such tricks are only in one direction. The files are uploaded to the server normally.

Answer 1

In general, I wrote to the hosting support, they lowered the MTU (Maximum Transmission Unit) to 1400, and everything worked as it should.

Answer 2

Vryatli the problem is in the server, sin on the client)
https://www.netsarang.com/en/free-for-home-school/
try

Answer 3

If the same garbage with other protocols, such as http (and / or ports, change the server settings to non-standard ones), then this is definitely a matter of hardware (or exotic firewall settings, if you have one) or your provider.
The latter is checked by trying to download something from your server 'from outside', for the purity of the experiment - from a new machine, or at least set up any public proxy.