After a while, port 80 shows as closed

Question

After 2 years uptime, my server with gitlab (on premise) can't be reached, because the nginx proxy server can not listen to port 80.

When I restart nginx it is usually working fine for 3 days or so. Right now, this happens in a seemingly random time - 12 hours, 15 minutes, inmediatly.

This nginx server has other reverse proxy configurations to reach other web servers. Which works fine but fails when gitlab is not reachable. If I test the machine with nmap, all other servers on my networks show me port 80 open, but not nginx.

NOTE: for this to debug, I shutdown firewalls on both servers.

From the nginx Machine:

Last login: Fri Jun 12 21:24:46 2020 from 192.100.100.101
avalle@nginxsrv:~$ nmap 192.100.100.190

Starting Nmap 6.40 ( http://nmap.org ) at 2020-06-12 21:52 MDT
Nmap scan report for 192.100.100.190
Host is up (0.0050s latency).
All 1000 scanned ports on 192.100.100.190 are closed

Nmap done: 1 IP address (1 host up) scanned in 0.26 seconds
avalle@nginxsrv:~$ sudo ifdown -a && sudo ifup -a
[sudo] password for avalle: 
avalle@nginxsrv:~$ nmap 192.100.100.190

Starting Nmap 6.40 ( http://nmap.org ) at 2020-06-12 21:52 MDT
Nmap scan report for 192.100.100.190
Host is up (0.00053s latency).
Not shown: 996 filtered ports
PORT    STATE  SERVICE
21/tcp  closed ftp
22/tcp  open   ssh
80/tcp  open   http
443/tcp closed https

Nmap done: 1 IP address (1 host up) scanned in 4.96 seconds
avalle@nginxsrv:~$

Are you sure your Gitlab is the only server with `192.100.100.190` IP address? 2 years uptime is bad, you have missed several security updates for the server. — Tero Kilkanen, Jun 13 '20 at 07:16
@bjoster nginx say 502 Bad gateway because the S.O. with nmap to 192.100.100.190 some times show the 80 port closed or simple dont show as a port open (not list) — Antonio Valle, Jun 14 '20 at 08:06
@TeroKilkanen yes, I reviewed some updates and I put a order to maintenance. for now I will reset the IP tables and apply security rule by rule — Antonio Valle, Jun 14 '20 at 08:11
So have you verified that there aren't other servers using the IP address? — Tero Kilkanen, Jun 14 '20 at 10:33
Yes I, I shutdown the gitlab server and the ping test show an unreachable host — Antonio Valle, Jun 15 '20 at 20:38

After a while, port 80 shows as closed

0 Answers0