rDNS error - mail.subdomain.domain.tld

Discussion in 'Installation/Configuration' started by MaddinXx, Nov 13, 2011.

  1. MaddinXx

    MaddinXx HowtoForge Supporter

    Hello everyone

    Once again, I need some help from professional guys like you all.

    Following the multiserver setup I created 4 virtual servers, which are OK. They are splitted as web (Web & DB), mail and ns1 & ns2.

    As I plan to add some more root server to my "network" sooner or later, I thought it would be cool to have a well organized domain structure, like this:

    servername.domain.tld (Node)
    web.servername.domain.tld (Virtual)
    mail.servername.domain.tld (Mail)
    and so on...

    Testing the mailserver with MXToolbox I got a rDNS does not match SMTP banner error.

    So I had a look at /etc/mailname which is correct, rDNS is set.
    I guess the problem is the hostname (is it checked for this?) which is still shown as mail only (but it should be mail.servername). However it does not seem to be possible to add dots in hostname.

    Is there any way I can realize my wish with the domain structure or is it simply not possible to have it like this - meaning it must always be mail.domain.tld?

    Thank you very much for solving my problem :)

    Greets,
    MaddinXx
     
  2. falko

    falko Super Moderator

    Do you have mail.servername.domain.tld in /etc/mailname?
    Does
    Code:
    telnet localhost 25
    show mail.servername.domain.tld?

    Does mail.servername.domain.tld exist as an A record?
     
  3. MaddinXx

    MaddinXx HowtoForge Supporter

    Hi falko

    /etc/mailname is set correctly.

    but telnet localhost 25 gives an command not found error.

    netstat -tna gives:

    Code:
    tcp        0      0 0.0.0.0:993             0.0.0.0:*               LISTEN     
    tcp        0      0 0.0.0.0:995             0.0.0.0:*               LISTEN     
    tcp        0      0 127.0.0.1:10025         0.0.0.0:*               LISTEN     
    tcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN     
    tcp        0      0 0.0.0.0:110             0.0.0.0:*               LISTEN     
    tcp        0      0 0.0.0.0:143             0.0.0.0:*               LISTEN     
    tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN     
    tcp        0      0 0.0.0.0:25              0.0.0.0:*               LISTEN     
    tcp        0      0 xxx.x.xxx.xx:22         xx.xxx.xxx.xx:50441     ESTABLISHED
    tcp6       0      0 :::22                   :::*                    LISTEN
    and A records are set correctly, meaning the records generated by the ISPConfig wizard as well as an A record for mail.subdomain pointing to the mailserver IP, and MX set to mail.subdomain.domain.tld.

    Regards,
    Michel
     
  4. falko

    falko Super Moderator

    Please install telnet...
    Code:
    apt-get install telnet
    ... and try again.

    Does
    Code:
    dig mail.servername.domain.tld
    show that it points to the correct IP?
     
  5. MaddinXx

    MaddinXx HowtoForge Supporter

    Hi falko

    Output of telnet localhost 25 is:

    Code:
    220 mail.alpha.rackster-server.ch ESMTP Postfix (Debian/GNU)
    and output of the dig command is:

    Code:
    ; <<>> DiG 9.7.3-P3 <<>> mail.alpha.rackster-server.ch
    ;; global options: +cmd
    ;; Got answer:
    ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40865
    ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
    
    ;; QUESTION SECTION:
    ;mail.alpha.rackster-server.ch.	IN	A
    
    ;; ANSWER SECTION:
    mail.alpha.rackster-server.ch. 86400 IN	A	176.9.221.50
    
    ;; Query time: 62 msec
    ;; SERVER: 192.168.1.254#53(192.168.1.254)
    ;; WHEN: Mon Nov 14 14:08:11 2011
    ;; MSG SIZE  rcvd: 63
    which is correct IP.

    Regards,
    Michel
     
  6. falko

    falko Super Moderator

    I've checked your hostname and the reverse record, and everything seems to be fine... :confused:
     
  7. MaddinXx

    MaddinXx HowtoForge Supporter

    Hi falko

    Oh lol just checked again with mxtoolbox and yep, it seems to be right for me too now.

    Really strange as I swear it wasn't before. Probably the Hetzner DNS took some while (long) to update their records.

    Thank you for the support & le'ts hope it stays as it is. :)

    Regards,
    Michel
     
  8. MxToolBox

    MxToolBox New Member

    Thanks for using our SMTP Diagnostic Tools...it does sound like the DNS wasn't quite updated, keep in mind that DNS changes can take 24-48 hours. I also wanted to let you know that in addition to the Free Tools on our website we also have a Free Monitoring Tool that will monitor any of the commands you can do on the website.

    Then our tool can automatically alert you if there is an SMTP, TCP, Blacklist issue. http://www.mxtoolbox.com/services_servermonitoring.aspx

    Thanks,
    @mxtoolbox
     

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