GS1920-48HP v4.70 VLAN issue

JZeman · January 2023

Hello everyone and please give me your opinion on this problem. I am trying to set up a simple input and output VLAN with number 5, but the configuration is misbehaving.

I have a device connected to port 1, untagged port vlan 5. On the output untagged port 45 vlan 5. I set a static IP address on the end device behind the port 45 and the VLAN does not work.

I only found the problem after exporting the configuration. VLAN 1 on ports 1-50 remains untagged even though I have set forbidden VLAN 1 for ports 1+45. If I manually edit the configuration and remove VLAN 1 untagged on ports 1+45, saved config import -> it suddenly works fine. How does this problem arise please? Thank you

Below exported configuration without modifications for correction:

vlan 1
name 1
normal ""
fixed 2-44,46-50
forbidden 1,45
untagged 1-50
ip address default-management 192.168.3.38 255.255.255.0
ip address default-gateway 192.168.3.254
exit

vlan 5
name xxx
normal 2-44,46-48
fixed 1,45,49-50
forbidden ""
untagged 1,45
exit

PeterUK · January 2023

The config view is not that clear when it says untagged

fixed = part of the VLAN

untagged = if its tagged or untag even if forbidden which if forbidden is forbidden and not part of the VLAN.

Sounds confusing better to view the GUI

in your case for:

VLAN1

forbidden 1,45

fixed 2-44,46-50 untag

PVID set to 1 for 2-44,46-50

VLAN5

forbidden 2-44,46-50

fixed 1,45 untag

PVID set to 5 for 1,45

JZeman · February 2023

Hi PeterUK, thank you very much for your response. I have attached some screenshots of the GUI. From the settings it shows that VLAN 1 is set as forbidden on the ports, but in the export it still shows as untagged. Am I doing something wrong please?

I only expect an untagged port when I set fixed without tx tagging.