Help configure trunk

Hi @AEK91

I'm not sure if the position of your GS1920 will be an access switch or an aggregate switch. Below are some guides for you to reference.

1. If it is an access switch, please configure the VLAN you have first. Then fix the ports that belong to this VLAN. Set eth48 as a tagged port and other ports as an untagged port.
   The below screenshots use port 1 as an access port and port 10 as the uplink port for example.
   a. Please navigate to Menu > Switching > VLAN > VLAN Setup > Static VLAN to configure your VLAN.
   
   
   b. Navigate to Menu > Switching > VLAN > VLAN Setup > VLAN Port Setup to configure port VLAN ID(PVID).
   
   This allows packets to be forwarded with a VLAN tag. In addition, VLAN 1 is a default VLAN which untags all ports by default.
   
   Here's a FAQ for you to reference:
   https://community.zyxel.com/en/discussion/19489/tutorial-of-switch-vlan-configuration-v4-80
2. If it is an aggregate switch, and you want to save time from setting VLAN, please configure VLAN trunking on the uplink port and eth48 at least.
   The below screenshot uses ports 1 and 10 as an example. Please navigate to Menu > Switching > VLAN > VLAN Setup > VLAN Port Setup to configure VLAN trunking.
   
   This allows packets from all VLANs to be forwarded with a VLAN tag if it has one.
   In addition, VLAN trunking will only forward packets from unknown VLANs. If the VLAN is created on GS1920, it will follow the VLAN setting to forward the packets.

Hope it helps.