Getting different nmap results from local machine and remote machines means there is some kind of firewall(whether running locally or some remote machine) which is blocking. According to the nmap documentation,
Nmap places ports in this state when it is unable to determine whether
a port is open or filtered. This occurs for scan types in which open
ports give no response. The lack of response could also mean that a
packet filter dropped the probe or any response it elicited. So Nmap
does not know for sure whether the port is open or being filtered. The
UDP, IP protocol, FIN, NULL, and Xmas scans classify ports this way.
I would recommend you to try out following tools to find out whether exactly the problem exists:
- To capture the UDP packets destined to
port 27960 using
tcpdump and . Check whether the packets are reaching your machine or not.
Run the following command to capture the udp packets destined to port 27960 in a file
$ sudo tcpdump -A 'udp and port 27960' -w tcpdump.out`
Try connecting from other machine to port using
$ nc <server-ip-address> -u 27960
Now stop the dump and check whether any packet got captured in the tcpdump.out or not using wireshark.
$ wireshark tcpdump.out
If no packet got captured, this means some intermediate device(firewall) is preventing the communication. Else, if captured check the reply which the server is giving in return of the request. If it is any kind of ICMP reply with some error code, it means there is some local firewall which is blocking.