[CentOS] Physically moving a mail server vs. cached DNS

Sat Jul 1 20:37:35 UTC 2017
Pete Biggs <pete at biggs.org.uk>

> You should check to see if your old SOA is still showing themselves
> as authoritative for your domain. If they are, then anyone who uses
> their nameservers will still get the old record(s) for your domain.
> 
> If they are still showing themselves as authoritative (which I think
> is the case) you will want to contact them to have them drop your
> domain from their server(s), or at least get your host records
> updated to point to your new servers. 
> 
Yes, that does seem to be the case.

Nicolas, if you make the query directly from the nfrance.com servers
you can see what we mean:

    $ host -a microlinux.fr ns.nfrance.com
    Trying "microlinux.fr"
    Using domain server:
    Name: ns.nfrance.com
    Address: 80.247.224.77#53
    Aliases: 

    ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 2088
    ;; flags: qr aa rd; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 7

    ;; QUESTION SECTION:
    ;microlinux.fr.    	    	    	    IN    	    ANY

    ;; ANSWER SECTION:
    microlinux.fr.    	    	    9600    	    IN    	    SOA    	    romeo.hebergement-discount.com. dns.nfrance.com. 2012081401 43200 1800 864000 9600
    microlinux.fr.    	    	    9600    	    IN    	    NS    	    ns2.slconseil.com.
    microlinux.fr.    	    	    9600    	    IN    	    NS    	    ns1.slconseil.com.
    microlinux.fr.    	    	    9600    	    IN    	    NS    	    ns3.slconseil.com.
    microlinux.fr.    	    	    9600    	    IN    	    MX    	    10 mx1.nfrance.com.
    microlinux.fr.    	    	    9600    	    IN    	    A    	    80.247.228.60

    ;; ADDITIONAL SECTION:
    ns1.slconseil.com.    	    432000    	    IN    	    A    	    80.247.224.77
    ns1.slconseil.com.    	    432000    	    IN    	    AAAA    	    2a00:1a60:22e0:4d00::1
    ns2.slconseil.com.    	    432000    	    IN    	    A    	    80.247.228.129
    ns2.slconseil.com.    	    432000    	    IN    	    AAAA    	    2a00:1a60:21e4:8100::1
    ns3.slconseil.com.    	    432000    	    IN    	    A    	    81.25.194.8
    mx1.nfrance.com.    	    60    	    IN    	    A    	    80.247.229.29
    mx1.nfrance.com.    	    60    	    IN    	    A    	    80.247.228.29

So nfrance.com still claim SOA on your domain. At least they have a
relatively short TTL on it of 9600s so things will correct themselves
quite quickly once they drop the domain.

P.