Troubleshooting 403 errors in agent checkin

Question

New install of ocsinventory, all modules on the same (debian) server.  /ocs-reports seems to be working fine now, but when I install the agent on a test machine it can't reach the server module located at /ocsinventory

The relevant line in the agent logs is:

ERROR *** AGENT => Failed to send Prolog <HTTP Status Code #403>

I've also tried manually pointing a browser at http://x.x.x.x/ocsinventory and I do indeed get a 403 error.  When I do the same from the server itself I get a blank page, which I assume is intended.

I do not have a firewall or any network-level blocks between the agent computer and the server.  I assume I have misconfigured something.

If I compare permissions between /usr/share/ocsinventory-reports and /usr/share/ocsinventory-server, the only difference is that /ocsinventory-reports is owned by www-data www-data and ocsinventory-server is owned by root root.  Is it possible that's the source of my problem? I'm hesitant to just go changing owners without fully understanding who the owner is *supposed* to be.

Answer 1

Went ahead and changed those permissions, to no avail.

Confirmed that ocsinventory-server.conf and z_ocsinventory-server.conf are the only files that touch the <location> /ocsinventory and they still have the default config:

---snip---

1. <Location /ocsinventory>
2. <IfModule mod_authz_core.c>
3. # Apache 2.4
4. Require all granted
5. </IfModule>
6. <IfModule !mod_authz_core.c>
7. # Apache 2.2
8. order deny,allow
9. allow from all
10. </IfModule>

---snip---

Answer 2

Where is yours checks of Apache configuration and Apache access log files ? Without these checks, there is no chance to solve ...

Please check : apache2ctl -S and access.log

Answer 3

Hi and thanks again Jacquesh, requested file snips are below:

Access.log: blank file. I think you may be more interested in...

Other_vhosts_access.log:

localhost:80 192.168.1.198 - - [20/Jun/2025:08:36:32 -0500] "GET /ocsinventory/deploy/label HTTP/1.1" 403 154 "-" "OCS-NG_WINDOWS_AGENT_v2.11.0.1"

localhost:80 192.168.1.198 - - [20/Jun/2025:08:36:32 -0500] "POST /ocsinventory HTTP/1.1" 403 154 "-" "OCS-NG_WINDOWS_AGENT_v2.11.0.1"

Apache2ctl -S output:

ocsinventory-server: Bad setting. `SNMP_LINK_TAG` is not set. Default: `0`

ocsinventory-server: Bad setting. `SCAN_TYPE_IPDISCOVER` is not set. Default: `ICMP`

ocsinventory-server: Bad setting. `SCAN_ARP_BANDWIDTH` is not set. Default: `256`

ocsinventory-server: Bad setting. `IPDISCOVER_LINK_TAG_NETWORK` is not set. Default: `0`

ocsinventory-server: Bad setting. `GENERATE_OCS_FILES_SNMP` is not set. Default: `0`

ocsinventory-server: Bad setting. `SCAN_TYPE_SNMP` is not set. Default: `ICMP`

VirtualHost configuration:

*:80                   localhost (/etc/apache2/sites-enabled/glpi.conf:1)

ServerRoot: "/etc/apache2"

Main DocumentRoot: "/var/www/html"

Main ErrorLog: "/var/log/apache2/error.log"

Mutex mpm-accept: using_defaults

Mutex watchdog-callback: using_defaults

Mutex rewrite-map: using_defaults

Mutex default: dir="/var/run/apache2/" mechanism=default 

PidFile: "/var/run/apache2/apache2.pid"

Define: DUMP_VHOSTS

Define: DUMP_RUN_CFG

Define: MODPERL2

User: name="www-data" id=33

Group: name="www-data" id=33

Bonus, Error.log:

https://pastebin.com/7CRUEpMc