How to update the ntp configuration for SuSE Linux servers?

This is using new Meinberg NTP appliance to replace the existing old one. This new one has been configured and operational right now. We have hundreds SuSE 11 servers and MS Windows 2008 or 2012 servers. All these servers sync to the existing ntp appliance for time, and being working fine for the past years.

We intend to replace this new one with the old one. Now, we are doing a test on the selected SuSE server. Please see the host names of these ntp appliances and 1 virtual name

                                        old ntp appliance:          sinaad21.abc.corp           192.168.1.3
                                        new ntp appliance:        sina3mbg01.abc.corp      192.168.1.4
                                        general ntp name:         sinntp01.abc.corp             192.168.1.11

We are using normal dns alias(or cname) for this ntp naming. Currently, sinaad21 is the alias pointing to sinntp01.abc.corp in our DNS server. Whereas, on all SuSE servers, in /etc/ntp.conf, a setting as below is configured,

                          sinntp01.abc.corp iburst

This is how we do the test with steps as follows,

                           a. On our DNS server, remove the alias of sinaad21, and change it to, sina3mbg01.
                           b. On a test SuSE server, restart the nscd to clear the dns cache.
                           c. On a test SuSE server, ping sinntp01.abc.corp, and we get the result of IP address of sina3mbg01(that means the alias is updated)
                           d. However, if we type "ntpq -p", we still get the result of old alias(sinaad21)

We can't afford to restart the ntp service on the test SuSE, as in production, none of the SuSE server is allowed to restart ntp service.

What can we do to update to use the new ntp appliance?

Thanks in advance