Score:0

Firewall blocking Port

bz flag

I am running multiple Webservices on my Ubuntu 22.04 Server and want them to bind to specific Ports which works without problem but when trying to connect it is not working and portchecker returned me that the Port is closed.

I tried to open the port via iptables, which did not work and ufw is not even installed. Do you know if there are other Firewalls on Ubuntu my hoster could have installed? I sent them an email but they just responded with something like "not our problem". When I nmap <domain> it says the port is open but portchecker says closed and I cant connect.

Outputs:

ss -tnlp | grep :444:

LISTEN 0      128                      *:444              *:*    users:(("symfony",pid=295662,fd=8))

nmap <domain> | grep 444:

444/tcp open  snpp

ufw status verbose | grep 444:

444                        ALLOW IN    Anywhere
444/tcp                    ALLOW IN    Anywhere
444/udp                    ALLOW IN    Anywhere
444 (v6)                   ALLOW IN    Anywhere (v6)
444/tcp (v6)               ALLOW IN    Anywhere (v6)
444/udp (v6)               ALLOW IN    Anywhere (v6)

telnet <domain> 444:

Trying <ipv4_adress>...
telnet: Unable to connect to remote host: Connection timed out

Thanks in advance for any response!

in flag
"closed" does not indicate a firewall issue. With a firewall it should be reported as "filtered". Please edit the output of your check commands into your question, along with the output of `ss -tnlp` for the wanted ports.
Zareh Kasparian avatar
us flag
my recommendation is to use netcat tool to make any port to listen mode, then trying to telnet to the port to check the connectivity. need to mention that telnet only work on TCP .
Konsti schwaigi avatar
bz flag
@GeraldSchneider Thanks for your answer! I added the outputs to the question.
Score:0
bz flag

Looks like it wasnt a Firewall fault. I was just stupid and made a : at the wrong place...

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