How to disable the message “reverse mapping checking getaddrinfo for xxx failed - POSSIBLE BREAK-IN...












3















I have a "OpenSSH_7.2" client connecting to a "OpenSSH_7.3-hpn14v5 FreeBSD-openssh-portable-7.3.p1,1" server hosted on a dynamic IP. The remote server is a NAS4free server.



I tried to apply the suggestions I found online and I added via WebGUI to the NAS4free sshd_config the following lines:



UseDNS no
GSSAPIAuthentication no


The client also has in sshd_config the same lines.



The message is still there. I have no access to the inverse DNS record, so I cannot change it.



I perform "quiet" remote rsync backups and the output is being sent by mail, since it only contains errors and warnings. I get an email every time for errors that are of no use in my case.



How should I solve the problem?










share|improve this question



























    3















    I have a "OpenSSH_7.2" client connecting to a "OpenSSH_7.3-hpn14v5 FreeBSD-openssh-portable-7.3.p1,1" server hosted on a dynamic IP. The remote server is a NAS4free server.



    I tried to apply the suggestions I found online and I added via WebGUI to the NAS4free sshd_config the following lines:



    UseDNS no
    GSSAPIAuthentication no


    The client also has in sshd_config the same lines.



    The message is still there. I have no access to the inverse DNS record, so I cannot change it.



    I perform "quiet" remote rsync backups and the output is being sent by mail, since it only contains errors and warnings. I get an email every time for errors that are of no use in my case.



    How should I solve the problem?










    share|improve this question

























      3












      3








      3


      1






      I have a "OpenSSH_7.2" client connecting to a "OpenSSH_7.3-hpn14v5 FreeBSD-openssh-portable-7.3.p1,1" server hosted on a dynamic IP. The remote server is a NAS4free server.



      I tried to apply the suggestions I found online and I added via WebGUI to the NAS4free sshd_config the following lines:



      UseDNS no
      GSSAPIAuthentication no


      The client also has in sshd_config the same lines.



      The message is still there. I have no access to the inverse DNS record, so I cannot change it.



      I perform "quiet" remote rsync backups and the output is being sent by mail, since it only contains errors and warnings. I get an email every time for errors that are of no use in my case.



      How should I solve the problem?










      share|improve this question














      I have a "OpenSSH_7.2" client connecting to a "OpenSSH_7.3-hpn14v5 FreeBSD-openssh-portable-7.3.p1,1" server hosted on a dynamic IP. The remote server is a NAS4free server.



      I tried to apply the suggestions I found online and I added via WebGUI to the NAS4free sshd_config the following lines:



      UseDNS no
      GSSAPIAuthentication no


      The client also has in sshd_config the same lines.



      The message is still there. I have no access to the inverse DNS record, so I cannot change it.



      I perform "quiet" remote rsync backups and the output is being sent by mail, since it only contains errors and warnings. I get an email every time for errors that are of no use in my case.



      How should I solve the problem?







      ssh dns openssh






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Nov 25 '16 at 22:50









      FarOFarO

      1,2181426




      1,2181426






















          1 Answer
          1






          active

          oldest

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          2














          The client appears to be calling the DNS check, therefore




          UseDNS no



          GSSAPIAuthentication no




          on the server are useless.



          The DNS check in the client has been introduced (apparently) with a GSSAPI patch introduced for compatibility with SunSSH [the file https://github.com/omniti-labs/omnios-build/blob/master/build/openssh/patches/0015-GSS-API-key-exchange-support.patch#L1652 is no more available online



          Adding




          GSSAPIKeyExchange no




          to ssh_config (not sshd_config) solved the issue.



          See also: https://www.mail-archive.com/omnios-discuss@lists.omniti.com/msg07240.html






          share|improve this answer


























          • links return 404 or host not found, can you update the links?

            – Jasonw
            Jan 9 at 1:25











          • @Jasonw The patch is gone, I cannot find it anymore. If you want you can search for the history of OpenSSH under OmniOS... I updated the link to the mailing list

            – FarO
            Jan 9 at 13:24











          Your Answer








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          1 Answer
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          active

          oldest

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          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          2














          The client appears to be calling the DNS check, therefore




          UseDNS no



          GSSAPIAuthentication no




          on the server are useless.



          The DNS check in the client has been introduced (apparently) with a GSSAPI patch introduced for compatibility with SunSSH [the file https://github.com/omniti-labs/omnios-build/blob/master/build/openssh/patches/0015-GSS-API-key-exchange-support.patch#L1652 is no more available online



          Adding




          GSSAPIKeyExchange no




          to ssh_config (not sshd_config) solved the issue.



          See also: https://www.mail-archive.com/omnios-discuss@lists.omniti.com/msg07240.html






          share|improve this answer


























          • links return 404 or host not found, can you update the links?

            – Jasonw
            Jan 9 at 1:25











          • @Jasonw The patch is gone, I cannot find it anymore. If you want you can search for the history of OpenSSH under OmniOS... I updated the link to the mailing list

            – FarO
            Jan 9 at 13:24
















          2














          The client appears to be calling the DNS check, therefore




          UseDNS no



          GSSAPIAuthentication no




          on the server are useless.



          The DNS check in the client has been introduced (apparently) with a GSSAPI patch introduced for compatibility with SunSSH [the file https://github.com/omniti-labs/omnios-build/blob/master/build/openssh/patches/0015-GSS-API-key-exchange-support.patch#L1652 is no more available online



          Adding




          GSSAPIKeyExchange no




          to ssh_config (not sshd_config) solved the issue.



          See also: https://www.mail-archive.com/omnios-discuss@lists.omniti.com/msg07240.html






          share|improve this answer


























          • links return 404 or host not found, can you update the links?

            – Jasonw
            Jan 9 at 1:25











          • @Jasonw The patch is gone, I cannot find it anymore. If you want you can search for the history of OpenSSH under OmniOS... I updated the link to the mailing list

            – FarO
            Jan 9 at 13:24














          2












          2








          2







          The client appears to be calling the DNS check, therefore




          UseDNS no



          GSSAPIAuthentication no




          on the server are useless.



          The DNS check in the client has been introduced (apparently) with a GSSAPI patch introduced for compatibility with SunSSH [the file https://github.com/omniti-labs/omnios-build/blob/master/build/openssh/patches/0015-GSS-API-key-exchange-support.patch#L1652 is no more available online



          Adding




          GSSAPIKeyExchange no




          to ssh_config (not sshd_config) solved the issue.



          See also: https://www.mail-archive.com/omnios-discuss@lists.omniti.com/msg07240.html






          share|improve this answer















          The client appears to be calling the DNS check, therefore




          UseDNS no



          GSSAPIAuthentication no




          on the server are useless.



          The DNS check in the client has been introduced (apparently) with a GSSAPI patch introduced for compatibility with SunSSH [the file https://github.com/omniti-labs/omnios-build/blob/master/build/openssh/patches/0015-GSS-API-key-exchange-support.patch#L1652 is no more available online



          Adding




          GSSAPIKeyExchange no




          to ssh_config (not sshd_config) solved the issue.



          See also: https://www.mail-archive.com/omnios-discuss@lists.omniti.com/msg07240.html







          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited Jan 9 at 13:24

























          answered Dec 4 '16 at 22:38









          FarOFarO

          1,2181426




          1,2181426













          • links return 404 or host not found, can you update the links?

            – Jasonw
            Jan 9 at 1:25











          • @Jasonw The patch is gone, I cannot find it anymore. If you want you can search for the history of OpenSSH under OmniOS... I updated the link to the mailing list

            – FarO
            Jan 9 at 13:24



















          • links return 404 or host not found, can you update the links?

            – Jasonw
            Jan 9 at 1:25











          • @Jasonw The patch is gone, I cannot find it anymore. If you want you can search for the history of OpenSSH under OmniOS... I updated the link to the mailing list

            – FarO
            Jan 9 at 13:24

















          links return 404 or host not found, can you update the links?

          – Jasonw
          Jan 9 at 1:25





          links return 404 or host not found, can you update the links?

          – Jasonw
          Jan 9 at 1:25













          @Jasonw The patch is gone, I cannot find it anymore. If you want you can search for the history of OpenSSH under OmniOS... I updated the link to the mailing list

          – FarO
          Jan 9 at 13:24





          @Jasonw The patch is gone, I cannot find it anymore. If you want you can search for the history of OpenSSH under OmniOS... I updated the link to the mailing list

          – FarO
          Jan 9 at 13:24


















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