Hello,
I upgraded my LibreNMS to the newest version yeasterday.
I have in my network some Cisco, Juniper and DCN devices. After this upgrade all my devices are recognized as DCN.
poller.php for Juniper MX204:
LibreNMS Poller
Starting polling run:
Hostname: mx204
Device ID: 1
OS: dcn-software
Resolved IP: 10.10.10.122
Load poller module core
Uptime: 1 year 66 days 11 hours 47 minutes 2 seconds
Runtime for poller module ‘core’: 0.0310 seconds with 50336 bytes
SNMP: [2/0.03s] MySQL: [0/0.00s] RRD: [1/0.00s]
Unload poller module core
Load poller module availability
Availability:
1 day : 100%
7 days : 99.008%
30 days : 99.769%
365 days : 99.981%
Runtime for poller module ‘availability’: 0.0086 seconds with 38880 bytes
SNMP: [0/0.00s] MySQL: [5/0.00s] RRD: [5/0.00s]
Unload poller module availability
Module [ unix-agent ] disabled globally.
Load poller module os
Generic 
Location: DC
Hardware:
OS Version:
OS Features:
Serial:
$ ./validate.php
| Component | Version |
|---|---|
| LibreNMS | 21.7.0-28-gcca484922 |
| DB Schema | 2021_25_01_0127_create_isis_adjacencies_table (211) |
| PHP | 7.3.29-1+0~20210701.86+debian10~1.gbp7ad6eb |
| Python | 3.7.3 |
| MySQL | 10.6.3-MariaDB-1:10.6.3+maria~buster |
| RRDTool | 1.7.1 |
| SNMP | NET-SNMP 5.7.3 |
====================================
[OK] Composer Version: 2.1.5
[OK] Dependencies up-to-date.
[OK] Database connection successful
[OK] Database schema correct
./daily.sh
Updating to latest codebase OK
Updating Composer packages OK
Updating SQL-Schema OK
Updating submodules OK
Cleaning up DB OK
Fetching notifications OK
Caching PeeringDB data OK
Caching Mac OUI data OK
./discovery.php -h mx204.mydomain.eu -m os -d
https://p.libren.ms/view/4143df6f
Any help will be appreciated.