Re: specifying local port on ftp client

You would need to allow for a local port range rather than a specific port, at least if you're also specifying a specific local interface. If you pick a specific local port and interface then after disconnecting you will have to wait before trying another connection to that same host (TIME_WAIT).

On 7/16/2020 1:54 AM, Bryan Dietz wrote:

I wonder if the open source lftp would allow for specifying the source port.

As I read the man page:
http://lftp.yar.ru/lftp-man.html <http://lftp.yar.ru/lftp-man.html>

I see some options that refer to local port:
ftp:port-ipv4 (ipv4 address)
specifies an IPv4 address to send with PORT command. Default is empty which means to
send the address of local end of control connection.

ftp:port-range (from-to)
allowed port range for the local side of the data connection. Format is min-max, or
`full' or `any' to indicate any port. Default is `full'.
Good luck

Bryan

On Jul 15, 2020, at 2:59 PM, Scott Klement <midrange-l@xxxxxxxxxxxxxxxx> wrote:

I'm not aware of any way to modify the "from port" of FTP (or, for that matter, most applications.) This is generally chosen at random by the OS from the ports that aren't in use.

FTP is even a bit more complicated since each time a directory listing or a file transfer occurs, it opens a separate port to do that. In active FTP, some clients allow you to configure an ephemeral port list, but typically this would not be used for passive FTP, and wouldn't be used for the control connection.

On 7/15/2020 2:46 PM, Rob Berendt wrote:

When I use my IBM i as an ftp client to connect somewhere is there a way to specify the local port I start out from?
I am not talking about the target port as in
open "delivery01-bld.dhe.ibm.com" 21
or
FTP RMTSYS("delivery01-bld.dhe.ibm.com") PORT(21)

Apparently getting someone to modify the permit list here is only done after exhausting all other avenues.

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