It is normal for firewalls to kill tcp connections that are idle for some period of time. This has nothing to do with DNS. You could adjust this idle period in your firewall, however it impossible to control the firewall of clients.
A solution is to use a disconnected model or send dummy requests from the applications to keep the connection active. Perhaps this link https://www.ibphoenix.com/resources/documents/how_to/doc_104 from a quick search provides another solution. From: firebird-support@yahoogroups.com [mailto:firebird-support@yahoogroups.com] Sent: Wednesday, May 31, 2017 15:48 To: firebird-support <firebird-support@yahoogroups.com> Subject: [firebird-support] remote connection disconnection Dear sir/madam, I am testing Firebird 3.0 in Ubuntu as DB Server. When application connects DB inside same network, everything works fine. When application connects DB through Internet (using Dynu DDNS service), connection may lose if there is not operation after period. I have checked firebird.conf and still not sure which parameter can avoid this issue. Or this issue is caused from Ubuntu ddclient DDNS service? Please give any advice to help me. Thanks. Best regards, James Venlig hilsen Thomas Kragh, Udvikler [uvdata logo] A part of KMD Stigsborgvej 60, 9400 N?rresundby E-mail t...@uvdata.dk Web www.uvdata.dk<http://www.uvdata.dk> Telefon +45 72287030 [http://res.uvdata.net/mailsignatur/kmdsammenudviklervidanmark.jpg] Vi g?r opmaerksom p?, at denne e-mail kan indeholde fortrolig information. Hvis du ved en fejltagelse modtager e-mailen, beder vi dig venligst informere afsender om fejlen ved at bruge svarfunktionen. Samtidig beder vi dig slette e-mailen i dit system uden at videresende eller kopiere den. Selvom e-mailen og ethvert vedhaeftet bilag efter vores overbevisning er fri for virus og andre fejl, som kan p?virke computeren eller it-systemet, hvori den modtages og laeses, ?bnes den p? modtagerens eget ansvar. Vi p?tager os ikke noget ansvar for tab og skade, som er opst?et i forbindelse med at modtage og bruge e-mailen. Please note that this message may contain confidential information. If you have received this message by mistake, please inform the sender of the mistake by sending a reply, then delete the message from your system without making, distributing or retaining any copies of it. Although we believe that the message and any attachments are free from viruses and other errors that might affect the computer or it-system where it is received and read, the recipient opens the message at his or her own risk. We assume no responsibility for any loss or damage arising from the receipt or use of this message.
