Vsol V1600G GPON OLT – ONU Serial Number not available via SNMP (shows 00:00:00:00:00:00)

Hi Team,

I am trying to monitor a Vsol (Fibersol) GPON OLT (V1600G) in LibreNMS and facing an issue with ONU identification.

  1. Added device in LibreNMS using SNMP v2c

  2. Device successfully discovered and polled

  3. ONU interfaces are visible under ports

  4. However, ONU MAC address shows as:

    00:00:00:00:00:00
    
  5. ONU Serial Number is not visible anywhere in LibreNMS

:cross_mark: Issue Details

  • ONU interfaces are discovered, example:

    GPON01ONU1 TEST-DEVICE-GPON001e166a
    
  • But:

    • MAC = 00:00:00:00:00:00

    • No ONU Serial Number via SNMP

./valiadate output-

Component Version
LibreNMS 26.3.1 (2026-03-17T14:55:34+05:30)
DB Schema 2026_03_05_112733_ospfv3_instances_nullable (374)
PHP 8.3.6
Python 3.12.3
Database MariaDB 10.11.14-MariaDB-0ubuntu0.24.04.1
RRDTool 1.7.2
SNMP 5.9.4.pre2
===========================================

[OK] Composer Version: 2.9.5
[OK] Dependencies up-to-date.
[OK] Database Connected
[OK] Database Schema is current
[OK] SQL Server meets minimum requirements
[OK] lower_case_table_names is enabled
[OK] MySQL engine is optimal
[OK] Database and column collations are correct
[OK] Database schema correct
[OK] MySQL and PHP time match
[OK] Active pollers found
[OK] Dispatcher Service is enabled
[OK] Locks are functional
[OK] Python wrapper cron entry is not present
[OK] Redis is unavailable