Migration and TTL value

Hello, im before migration of hosting accounts from one cpanel server to another.

My aim is to lower the TTL value of the nameservers so the ISP of website visitors dont keep old server IP value too long and its quickly rechecked and get new IP value from nameservers.

My question is this:

Do i need to change DNS zone file on my old hosting server and set lower TTL value? Or i need to change TTL value on my domain registar where i have nameservers registered?

Which one has priority and which one is taken into account by internet service provider?

In my case i cant change TTL on my domain registar side (Namecheap appears not to allow change and it is 48 hours TTL)

So would be good if DNS zone files TTL has priority? thanks

 

Thanks for clear reply, ok i change value, but can you explain why is not needed to change TTL on domain registar side? And please answer my question "Which one has priority and which one is taken into account by internet service provider?"

(im speaking about ttl on registar side and hosting server side)

thx

 

thx, is there any way i can veriffy that low TTL value in DNS zone file on my cpanel server will really make ISP to get new IP data quicker?
Any online tool any linux command?

This tool checks resolved IP for a domain name: http://cachecheck.opendns.com/

Here is the zone file:


So i need to change all 86400 values please? I dont see TTL A value, only NS and SOA...

Linux command to see TTL values:

Code:

dig @ns3.nameserver.com -t A www.domainpointedtothatnameserver.com

It returns 86400 so appears this value is taken by ISP

On above attached image there is 4 times 86400 value, do i need to change all these for lowering cache time os ISP? Named, Bind restart is needed?

 

Thx Michael, but im not having SSH access and my provider told he wont do it, thats why im asking in my previous post..