If you aren't the admin of your server, how do you even know some IP
is hitting your server's IP address at port 1500?
Anyway, that is an issue that would require escalation to root to address
properly although you can do some limiting by blacklisting the IP in your
regular web and email applications.
For escalated access, you could block the IP at the specific port with
most firewalls or just directly in the server with iptables:
To entirely drop an IP address entirely from hitting your server:
Code:
# iptables -A INPUT -s xx.xx.xx.xx -j DROP
To limit a specific IP from accessing port 1500 in this case:
Code:
# iptables -A INPUT -s xx.xx.xx.xx -p all --dport 1500 -j DROP