Ok, so I've been running an ISPconfig server for years now without any problem, now we are switching links and along with that comes new IPs. So I changed the IP in the interface, hosts and in all the NS listed inside ispconfig. After that some websites do work, I can not get to the admin page anymore, email are not working either way in or out, FTP is working fine. I ran updates and ispconfig update to let it reconfigure everything. Did I miss something?
