AFAIK, your best bet in this case would be to increase the TTL of your DNS entries prior to the migration and to manually ensure to restore them once control has been transferred ASAP because they will be overwritten with (usually unwanted) default values at that point. This way, frequent users of your website/services should not be affected (unless they clear their local DNS caches on a regular basis).
Unfortunately, you still cannot overwrite said default values with your own settings to take effect at the time the transfer succeeds. That's one of the items of the "joint wish list" for many users of this forum.
your best bet in this case would be to increase the TTL of your DNS entries prior to the migration and to manually ensure to restore them once control has been transferred
PMJI, but you certainly want to decrease the TTL to shorten migration time ... probably a typo, only 
Edit: Not in this case, refer to m_ueberall ...
PMJI, but you certainly want to decrease the TTL to shorten migration time ... probably a typo, only
OP said that s/he already uses a Netcup server which means that the current DNS settings are valid (as I read it) and it's about transferring control over DNS entries to another registrar. In this case, increasing the TTL ensures that caches won't get refreshed before s/he has had a chance to ensure that the next refresh will not result in wrong (default) DNS entries.
In case you need to change the IP address of a server, you'd want to decrease the TTL beforehand to ensure that existing caches get refreshed as soon as possible.
In this case, increasing the TTL ensures that caches won't get refreshed before s/he has had a chance to ensure that the next refresh will not result in wrong (default) DNS entries.
I stand corrected. Thanks for clarifying ... I should have kept my mouth shut, but just wanted to avoid some misunderstanding: My bad... 
AFAIK, your best bet in this case would be to increase the TTL of your DNS entries prior to the migration
Thanks for the quick reply, and sorry for the late reply: I did not get a notification when I got answers.
The issue is I don't get access to DNS prior to migration. I only get access to the domain DNS once the migration has been done.
Also, any idea who I can reach, my domain has been "in migration" for 5 days, although the auth token was entered...
The issue is I don't get access to DNS prior to migration. I only get access to the domain DNS once the migration has been done.
Also, any idea who I can reach, my domain has been "in migration" for 5 days, although the auth token was entered...
millerf : If your current/old service provider (g****.net) whose name servers are still associated with your domain does not allow you to modify the TTL values, you're out of luck, unfortunately.
# dig SOA +multiline nomad-park.com
[…]
;; ANSWER SECTION:
nomad-park.com. 14205 IN SOA ns1.g****.net. hostmaster.g****.net. (
1732147200 ; serial
10800 ; refresh (3 hours)
3600 ; retry (1 hour)
604800 ; expire (1 week)
10800 ; minimum (3 hours)
)As a netcup customer, I'd suggest to contact their support as documented here.