Replacing time.windows.com with a local ntp server

Democracy is the art of controlling the circus from within the monkey cage.
Henry Louis Mencken

In large, constantly changing and developing heterogeneous networks, setting the address of the local ntp server on all machines can be a problem. In this case, you can use the capabilities of the BIND DNS server and replace the IP address that is issued upon request of “time.windows.com”.

On the DNS server (using SLES 10 as an example), we will create the zone of our interest with the following content:

/var/lib/named/master/time.windows.com

$ TTL 2d                                                                         
@ IN SOA ns.example.com. root.ns.example.com. (           
                                2009012810; serial                        
                                3h; refresh                       
                                1h; retry                         
                                1w; expiry                        
                                1d); minimum                       
time.windows.com. IN NS ns.example.com.                          
time.windows.com. IN A 192.168.0.1

where 192.168.0.1 is the IP address of the local ntp server

In the configuration file /etc/named.conf we add the lines:

zone "time.windows.com" in {                                                    
    file "master / time.windows.com";                                             
    type master;                                                                
    allow-transfer {acls; };               
};

where '' 'acls' '' are the ACLs used in the local network and we

Overload Bind:

 rcnamed reload

If everything is correct in the log / var / log / messages, a similar line will appear:

 May 24 08:17:32 ns named [30279]: zone time.windows.com/IN: loaded serial 2009012810

We check the result on the client machine by first flushing the dns cache ( How_do_I_Flush_DNS? ):

# ping time.windows.com
PING time.windows.com (192.168.0.1) 56 (84) bytes of data.
64 bytes from ntp.example.com (192.168.0.1): icmp_seq = 1 ttl = 254 time = 0.896 ms