Unable to remote access the web server running on Ubuntu machine

roXx

6/7/24, 12:21 PM

I'm unable to remote access nginx server or express server or any server running on Ubuntu in the same network I tried every solution found on Google, chat gpt but no benefit I'm able to ssh on Ubuntu machine even tried disabling firewalls, creating rules for port, but no benefit

udp       UNCONN     0          0                127.0.0.53%lo:53                   0.0.0.0:*
udp       UNCONN     0          0                      0.0.0.0:123                  0.0.0.0:*
udp       UNCONN     0          0                    127.0.0.1:323                  0.0.0.0:*
udp       UNCONN     0          0                      0.0.0.0:631                  0.0.0.0:*
udp       UNCONN     0          0                      0.0.0.0:5353                 0.0.0.0:*
udp       UNCONN     0          0                      0.0.0.0:56376                0.0.0.0:*
tcp       LISTEN     0          511                    0.0.0.0:8080                 0.0.0.0:*         users:(("node",pid=90596,fd=20))
tcp       LISTEN     0          511                    0.0.0.0:8000                 0.0.0.0:*
tcp       LISTEN     0          4096             127.0.0.53%lo:53                   0.0.0.0:*
tcp       LISTEN     0          4096                 127.0.0.1:2947                 0.0.0.0:*
tcp       LISTEN     0          128                  127.0.0.1:631                  0.0.0.0:*
tcp       LISTEN     0          1                      0.0.0.0:5000                 0.0.0.0:*
tcp       LISTEN     0          511                    0.0.0.0:80                   0.0.0.0:*
tcp       LISTEN     0          128                    0.0.0.0:22                   0.0.0.0:*

tcpdump of port 8080

16:32:08.115917 IP (tos 0x0, ttl 128, id 58161, offset 0, flags [DF], proto TCP (6), length 52)
    192.168.1.103.62897 > sipl-NUC7PJYH.http-alt: Flags [S], cksum 0x92cf (correct), seq 887362367, win 64240, options [mss 1460,nop,wscale 8,nop,nop,sackOK], length 0
16:32:08.116189 IP (tos 0x0, ttl 128, id 58162, offset 0, flags [DF], proto TCP (6), length 52)
    192.168.1.103.62898 > sipl-NUC7PJYH.http-alt: Flags [S], cksum 0xf4d8 (correct), seq 1565558984, win 64240, options [mss 1460,nop,wscale 8,nop,nop,sackOK], length 0

1 + 0

server

iptables

firewall

networking

Score:0

Ubuntu

maniac_on_moon

6/7/24, 12:46 PM

have you tried to check the IP using ping and the tcp port using nmap for a successful threeway tcp handshake? Can you reach the machine via ssh? Just asking, since we see only packets flowing in one direction.

Can you reach the default webpage of the nginx? Can the nginx process read the content? Are there any logs?

There is no general answer to that problem.

Kind Regards maniac__

+ 6

roXx

6/7/24, 12:51 PM

the IP is pingable, nmap showing 8080, 8000, 80 as filtered port, i am able to ssh also, default page is showing content of node on default machine

maniac_on_moon

6/7/24, 12:58 PM

Can you find the clients source IP in the logs of the nginx? "Filtered means that a firewall, filter, or other network obstacle is blocking the port so that Nmap cannot tell whether it is open or closed. "

roXx

6/7/24, 1:01 PM

I can but leave nginx, I can't even access the simple node server or cups print server running, I even disabled the ufw and flush the iptables

maniac_on_moon

6/7/24, 1:27 PM

your first answer shows the way: it seems like a firewall issue, either on your client or the server.

roXx

6/7/24, 1:34 PM

to me, it looks like an OS issue because I tried everything with firewall, even used different clients, and tried in different networks also with different interfaces as well.

Jakke

6/13/24, 1:18 PM

Hey, usually when you have questions to the OP, you post it as a comment. When you have a full picture of the issue and you think you have a solution, then print it out in full in a solution. You always have to think about someone else visiting this site to solve a problem. They expect to see a solution right in front of them, not having to dig through all the comments. Otherwise, great to have you onboard and I'm sure you'll get the hang of things soon.

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