GS1900 24HP - Configure VLAN and LAG interface

tinckle11

Hello ! I was given this switch for Christmas and, as I'm still a networking student, I haven't mastered everything, so I could really use your help.

Here's my architecture:

OPNSense (Port 1/LAN) → SG1900 (Port 1)
OPNSense (Ports 3&4) → SG1900 (Ports 23&24)
SG1900 (Port 9) → PC (DHCP Enabled)

I wanted to make sure that Ports 1 are used to manage the switch, so they'll be in VLAN 1. Ports 3&4 (OPNSense) are in LAG.

As I understand it, the LAG interface needs to be in Trunk Link so that VLAN-tagged packets can communicate with VLAN addresses at the OPNSense router (which will act as default gateway and DHCP servers).

Interfaces where end devices are connected will receive Untagged packets.

Based on these principles, I've tried to implement this configuration:

The configuration windows look simple, but I can't figure out what's wrong.

I tried a few manipulations:
When I connect the PC to any port other than 9 to 16, I receive an IP address from the OPNSense server, which is assigned to hosts connecting via the LAN interface, and I have access to the Internet.

When I connect the PC to a port between 9 and 16, I no longer have any contact with my OPNSense router. I can't contact it via the Virtual Interface address, and when my network card sends DHCP packets in Broadcast, OPNSense doesn't respond.

Thank you for your help, I've never used a ZyXel switch before.

Zyxel_Judy

HI @tinckle11 ,

It appears your switch configuration is correct. Please check and troubleshoot the OPNsense router to determine why it's not responding to packets.

Zyxel_Judy

HI @tinckle11 ,

It appears your switch configuration is correct. Please check and troubleshoot the OPNsense router to determine why it's not responding to packets.

tinckle11

Thank you for confirming. There is one point on the configuration that seems rather vague to me, and that is the configuration of ports 23&24 and LAG1.
Does one have priority over the other, and if the settings for port 23 and 24 are not identical, does this affect the LAG1 port?
If I don't configure ports 23&24 but only LAG1, will ports 23&24 also adopt this configuration?

Zyxel_Judy

Hi @tinckle11 ,

For LAG1 (ports 23+24), you only need to configure settings on LAG1 itself. There's no need to configure individual ports.

For instructions on configuring VLAN settings for Link Aggregation on GS1900 series switches, please refer to the FAQ below.

https://community.zyxel.com/en/discussion/4206/how-to-set-vlan-setting-for-link-aggregation-in-gs1900-series