Are the clients allowed to access your domain to connect to the server or are they trying to access from a local station?
If the server can ping to the clients and your clients can’t ping to the server, the server firewall is blocking the port(s).
You can either turn the firewall off or set exceptions for the applications you need access to.
in improving on mshen response;
you should also find out if some of the server’s configs are well done to allow what you are anticipating for, eg check its firewall configs – though its advisable to turn on the firewall but check on the ‘exceptional programs’ radio button to at least allow the clients access the server. the dhcp config should also be well done
for the problem may be elevating from this.