NCPA - '[Errno 104] Connection reset by peer'

[jjung_clarins]

Hello,

i have a problem on a Windows 2012R2 Server to make agent fetch informations.
No change on the server but i get message
"UNKNOWN: An error occured connecting to API. (Connection error: '[Errno 104] Connection reset by peer')"
for every check on the sever.

When using wizard to re-add the server, i get "Unable to contact server at https://xxx.xxx.xxx.xxx:5693/testconnect/?token=.
"
I've tried to change SSL version, no luck.

I well telnet from the nagios server to the server on 5693.

I've installed last NCPA, 2.4, same results.
NagiosXI version is 5.7.2.

Does someone had this error ?

Thanks

[nagiostra]

Did it work as expected at some point and then start giving you this error?

[jjung_clarins]

Absolutely !

[nagiostra]

It looks like a firewall issue. Typically this would be the Windows server saying I'm here, and I'm listening, but I'm not going to let you connect. Can you think of any changes you made on the Windows server in between when it worked and when it didn't?

[nagiostra]

It looks like a firewall issue. Typically this would be the Windows server saying I'm here, and I'm listening, but I'm not going to let you connect. Can you think of any changes you made on the Windows server in between when it worked and when it didn't?

[jjung_clarins]

Windows firewall is disabled :/
And i well connect using telnet...
I have Palo Alto in between, didn't try a permissive rule only for this as i don't see any drops

[nagiostra]

Run these three commands from the command line on your XI host and post the results:
nmap https:ip_of_windows_host:5693
curl -v https:ip_of_windows_host:5693/ -k
telnet ip_of_windows_host 5693

[nagiostra]

Actually, the first command should be:
nmap ip_of_windows_host:5693

My bad. Copy/Paste mistake

[jjung_clarins]

Here's the result
[root@xxxx~]# nmap https:xxx.xxx.xxx.xxx:5693

Starting Nmap 6.47 ( http://nmap.org ) at 2022-12-06 17:59 CET
Failed to resolve "https:xxx.xxx.xxx.xxx:5693".
WARNING: No targets were specified, so 0 hosts scanned.
Nmap done: 0 IP addresses (0 hosts up) scanned in 0.04 seconds
[root@xxxx~]# nmap xxx.xxx.xxx.xxx:5693

Starting Nmap 6.47 ( http://nmap.org ) at 2022-12-06 18:00 CET
Failed to resolve "xxx.xxx.xxx.xxx:5693".
WARNING: No targets were specified, so 0 hosts scanned.
Nmap done: 0 IP addresses (0 hosts up) scanned in 0.03 seconds
[root@xxxx~]# curl -v https:xxx.xxx.xxx.xxx:5693/ -k
* getaddrinfo(3) failed for https:xxx.xxx.xxx.xxx:5693
* Couldn't resolve host 'https:xxx.xxx.xxx.xxx'
* Closing connection #0
curl: (6) Couldn't resolve host 'https:xxx.xxx.xxx.xxx'
[root@xxxx~]# telnet xxx.xxx.xxx.xxx5693
Trying xxx.xxx.xxx.xxx...
Connected to xxx.xxx.xxx.xxx.
Escape character is '^]'.
^CConnection closed by foreign host.

[nagiostra]

Sorry, remove the :5693 from the command. Should be ip_of_windows_host