[Samba] A records of computers in domain take long to update

[Mikel Pérez]

hey there :) don't know why but it takes a while before I can reach
computers in my AD network by their hostnames. I often have to end up
looking for them at the router's status page (OpenWrt)
is it because I'm letting the router be the DHCP server instead of my samba
AD DC? if that's the case, how should I go on about setting the DC to be
the DHCP server and how do I link it to samba? if it isn't, then what
should I do so that the computers hostnames point to their IP addresses as
soon as they're assigned to them by the router?

thanks!!