I cant open port on ubuntu 20.04 desktop

Engin Hançerli

12/14/23, 5:46 AM

I have Ubuntu 20.04 installed desktop pc.Ufw is inactive and all the modem port forwarding properly done.My problem is I cant open the ports to outside.For example 8765 port is listening on ubuntu but when I check the port checker I see that it is closed. Also when I check via 'sudo tcpdump -n icmp' command it shows icmp unreachable - admin prohibited To solve this I installed firewalld and gave permission to that ports via firewalld but no help.And then I uninstalled it.

This port is used by a node called bazuka.Also I have problems with other ports too.

For port 22, I installed ssh server and just port 22 shows open on yougetsignal port checker.

I am confused about ufw, iptables and nftables configuration.

If you need further information, I can write

root@desktop:~# sudo ufw status
Status: inactive

root@desktop:~# netstat -nltp | grep 8765
tcp        0      0 127.0.0.1:8765          0.0.0.0:*               LISTEN      118491/bazuka       

root@desktop:~# sudo lsof -i :8765
COMMAND    PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
bazuka  118491 root   13u  IPv4 420114      0t0  TCP localhost:8765 (LISTEN)

root@desktop:~# sudo tcpdump -n icmp
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on wlp6s0, link-type EN10MB (Ethernet), capture size 262144 bytes

285

0 + 1

firewall

networking

ufw

port-forwarding

Alejandro

12/14/23, 10:31 AM

Can you please edit your question and be more specific? Which port you are trying to open, which type of traffic it is going to handle (TCP or UDP), which service it is for, which commands you tried... I'm glad to help you with `ufw` but I need some more info.

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