NebulaFlex Switch GS1920 Series - V5.00 Patch 2 Firmware Release

Zyxel_Melen

Zyxel Switch GS1920 Series Release Note 

October 2025

Firmware Version on all models

(Click Hyperlink to download the firmware directly)

Zyxel GS1920-8HPv2 - V5.00(ABKZ.2)C0

Zyxel GS1920-24v2 - V5.00(ABMH.2)C0

Zyxel GS1920-24HPv2 - V5.00(ABMI.2)C0

Zyxel GS1920-48v2 - V5.00(ABMJ.2)C0

Zyxel GS1920-48HPv2 - V5.00(ABMK.2)C0

New Feature and Enhancements

1. [Nebula 19.10] Support Port advisor. 

2. [Nebula 19.20] VLAN ingress check enabled by default. 

3. [Standalone, Nebula] MAC-auth support attribute: NAS-Port, NAS-Port-Type, Framed- MTU, state, calling-station-id, message-authenticator.

Bug Fix

C=Cloud mode, S=Standalone mode

Bug fix	C	S
1. [eITS #241200595] Fixed high CPU usage triggered by client switching between trunk interfaces.	V	V
2. [eITS #250200357] Switch has dropped the EAPoL unicast packet.	V	V
3. [eITS #250200815, 250400367] After deleting original and creating another mgmt VLAN and IP, pinging the new mgmt IP over LACP links will fail if one of the LACP member ports is inactive.	V	V
4. [eITS #250301742, 250600412] Supplicants that have successfully passed 802.1X authentication may still be incorrectly assigned to guest VLAN if the reachability of RADIUS server is unstable.	-	V
5. [eITS #250302188] MAC-auth via Nebula cloud authentication becomes significantly slower in authenticating supplicants after a reboot.	V	-
6. [eITS #250302409] Fixed the device sometimes fail to connect with Nebula server.	V	-
7. [eITS #250500429] Fixed crash when receiving IPv6 tunnel packet.	-	V
8. [eITS #250500683] Voice VLAN (via LLDP MED) does not work properly when enabling MAC-auth under Nebula cloud authentication.	V	-
9. [eITS #250800443] Special characters in the port name cause the port Bug fix Nebula Standalone information to appear blank on the Dashboard.	V	V
10. [eITS #250900392] Restoring or reloading the configuration results in an error if the time range profile name contains spaces.	-	V
11. [eITS #250900428] The date format in the backup configuration file name becomes incorrect when Daylight Saving Time is enabled.	V	V

Please refer to the Download Link for more details.