Force lftp to open binary connections? - bash

Question

The problem: I am trying to create a local mirror of a public FTP site. When I use lftp to do the job it creates a mirror without a problem, but when I try to update the mirror a few days later it becomes very slow due to getting stuck on several files.
Running lftp -d I can see that lftp makes several requests to RETR the file, but these requests result in several **** Timeout - reconnecting messages and after about 2-3 minutes I see
<--- 150 Opening BINARY mode data connection for {filename removed}.`
After this last command the file successfully downloads and lftp proceeds further.
From the manual I understand that BINARY is the default mode for lftp, but somehow it doesn't seem to work for the early requests. Can someone suggest how I can force lftp to always open BINARY mode data connection to download all files?
Here's a MWE:
``lftp -d -u anonymous,anonymous -c "open {url}; get {file}"``
And response from lftp -d:
---- Connecting to {url} ({IP}) port 21
<--- 220 (vsFTPd 3.0.3)
---> FEAT
<--- 211-Features:
<--- EPRT
<--- EPSV
<--- MDTM
<--- PASV
<--- REST STREAM
<--- SIZE
<--- TVFS
<--- 211 End
---> USER anonymous
<--- 331 Please specify the password.
---> PASS anonymous
<--- 230 Login successful.
---> TYPE I
<--- 200 Switching to Binary mode.
---> SIZE {file}
<--- 213 3321
---> MDTM {file}
--- 213 20160318190446
---> PASV
<--- 227 Entering Passive Mode ({IP}).
---- Connecting data socket to ({IP}) port 55380
---- Data connection established
---> RETR {file}
**** Timeout - reconnecting
---- Closing data socket
---- Closing control socket

Answer 1

lftp uses binary mode by default for all file transfers and ascii mode for directory listings. So the binary mode should not be a problem here.
Maybe you have a subtle connectivity problem, sometimes setting net:socket-maxseg to a lower value (e.g. 500) helps.

Answer 2

The ftp command for binary mode is bin so use that command before you get the file.
cd /direc/tory; bin; get file.xml
The problem is that I see
---> TYPE I
<--- 200 Switching to Binary mode.
in your output, so you're already in binary mode. I wonder if you have a different problem? I also see that you're using passive mode (PASV), and that's good because passive works around firewalls and NATs [1], so we need another reason why you see those timeouts.
Do you have any other clues, maybe from ping or netstat?