DNS Server Config Change

[40mb]

We have flapping going on again today with the our ISP DNS servers. Is it OK to change the DNS servers during production hours? Will it cut connectivity for all when I make the config change?

[DarrenOC]

Where are you making your DNS changes?  On the MX itself or DNS for your end user clients?

[40mb]

On the MX

[DarrenOC]

You’ll be fine.

Are your LAN dhcp scopes setup to use the upstream DNS servers that your MX use?

- Proxy to upstream DNS?

even in that instance I doubt your users will notice anything 

[pmhaske]

Hi @40mb,

I agree with @DarrenOC, if you are making changes on the MX WAN interface for its management DNS servers it should not affect clients' DNS. Keep in mind that, if you have your DHCP scope set to Proxy to upstream DNS, clients with existing DHCP lease will get the updated DNS server when they renew their lease and new clients will get updated DNS servers immediately with the new lease.