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  • 1.  FTP issue on 7.4

    Posted Tue August 30, 2022 11:03 AM
    Upgraded to IBMi 7.4 in early July. Around that time, we turned off FTP & began utilizing SFTP. Needed to turn FTP back on temporarily (AWLSSL *YES). Cannot connect when not on LAN (via VPN or branch-office VPN). When on LAN, cannot connect via FileZilla or WinSCP, but ok via DOS prompt

    Opened case with IBM. Cannot find anything wrong with FTP on IBMi. Seems like a firewall issue - but FileZilla & WinSCP on LAN has me baffled. Rebooted firewall - no dice.

    Was working fine on 7.3 - don't know if 7.4 upgrade caused it or if unrelated. From communication traces, IBM states ACK never acknowledged via client.

    On VPN - via DOS prompt

    FTP <IP address>
    Connected to <IP address> Connected via FTP
    220 Connection will close if idle more than 5 minutes
    User <IP address>:(none): <my userID>
    501 OPTS unsuccessful; specified subcommand not recognized.
    Login failed.
    ftp> quit

    After "Logon failed", I receive ftp> when I type in quit I receive 331 Enter password. Followed by return to DOS prompt. There is no noticeable delay between commands - response is (near) instantaneous.

    Strange thing is if going into FTP from the DOS prompt when on VPN IMMEDIATELY after starting FTP on IBMi, it may work (which is telling me NOT a firewall issue) - but only for that initial connection.

    When using FileZilla or WinSCP with implicit connection (on the LAN & over VPN), will be presented with certificate & then fails.

    I only plan on turning FTP on only when needed & immediately end once no longer needed.  I'm just baffled because for years, we've used FTP server on our​​ IBMi & have never experienced an issue like this.  If infrastructure (firewall, ISP, etc) changed, I could see this being caused by external factors.  Just completely baffled & am hoping someone can help me resolve this.

    Thank you
    -Dan

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    Dan Devoe
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  • 2.  RE: FTP issue on 7.4

    Posted Sun February 19, 2023 10:39 AM

    I've seen many issues with ftp on the i.  Most of them are externally caused.  I've seen switch ports cause issues.  Work fine will all other traffic but sometimes not FTP.  Make sure that the network adapter is feeding through an enterprise type switch and not one of those interim dinky switches or hubs.  I give them the sign of the cross and chuck them.  They should not be in your network connection from the adapter.  If it is going to an enterprise network switch, try moving the cable to another port.  Switch diagnostics may not show an issue with this.  I've fixed many a ftp issue by doing the above.



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    Jim
    Wannabe Curmudgeon...
    Senior Systems Engineer
    CAS Severn, Inc
    Laurel, MD
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    Original Message