Error 6909#100185 - Logged under Status/System Logs/System/General

[mmeshurle]

I have these four errors reported by a client, then connectivity drops. I searched the forums and could not locate anything related to something similar to this error.
The 192.168.1.9 is a DNS/Primary DC. DNS from Windows goes out of the network for any local resolution (1.1.1.1).
There are two DCs/DNS servers on the network with no issues with the DCs and replication is good.
Any guidance would be appreciated!

May 3 14:20:18 nginx 2023/05/03 14:20:18 [error] 6909#100185: *54790 open() "/usr/local/www/HNAP1" failed (2: No such file or directory), client: 192.168.1.9, server: , request: "GET /HNAP1 HTTP/1.1", host: "192.168.1.254:444"

May 3 14:20:18 nginx 2023/05/03 14:20:18 [error] 6909#100185: *54789 open() "/usr/local/www/sdk" failed (2: No such file or directory), client: 192.168.1.9, server: , request: "POST /sdk HTTP/1.1", host: "192.168.1.254:444"

May 3 14:20:18 nginx 2023/05/03 14:20:18 [error] 6909#100185: *54788 open() "/usr/local/www/evox/about" failed (2: No such file or directory), client: 192.168.1.9, server: , request: "GET /evox/about HTTP/1.1", host: "192.168.1.254:444"

May 3 14:20:18 nginx 2023/05/03 14:20:18 [error] 6909#100185: *54787 open() "/usr/local/www/nmaplowercheck1683138018" failed (2: No such file or directory), client: 192.168.1.9, server: , request: "GET /nmaplowercheck1683138018 HTTP/1.1", host: "192.168.1.254:444"

[SteveITS]

@mmeshurle Define “connectivity drops”?

Is there a probe or scanner running on that server that would be making http requests to devices on the network?

You could create a firewall rule to block 80/443 from that server IP. That’s masking the issue though.

[jimp]

192.168.1.9 is apparently running an nmap scan against the firewall and the GUI port is open to it, so its requests are being processed by the firewall's web server. Searching the files being requested they come back to various aspects of nmap scan/test probes.

It's hard to say what might be causing a connectivity loss, but I'd start by making sure 192.168.1.9 isn't compromised in some way and causing local network issues.

Also, lock down the rules so only approved local management hosts can reach the firewall. Anything else should only blocked with exceptions to pass DNS and other local service ports and ICMP depending on what's running on the firewall.

[mmeshurle]

@jimp Damn it. Should of looked further. We deploy Atera RMM and I have a scanning agent on that server/IP. I will take the router out of the scan.
Thanks @jimp for catching that!