ZyXel GS1920 Switch w/ VLAN

Question

This may be a relatively easy question. However it's giving me a headache this morning. I have a ZyXel GS1920-48HP. Last week it lost its config. So I have to reconfigure. This switch had three vlans and as I'm reconfiguring the new VLANs aren't working

Ports 1-44 VLAN 1 (Fixed) Untagged

Ports 45-46 VLAN 2 (Fixed) Untagged

Ports 47-48 VLAN 3 (Fixed) untagged

1-44 are my production network going with connections going to PCs and one to LAN INT on router

45-46 are public wireless one going to POE access point, other going to LAN2 INT on router

47-48 are going to a private wireless AP that has to be a separate LAN, other going to configured WLAN port on router.

As of right now VLANs cannot communicate with each other, which is correct. All ports in VLAN 1 are fine. VLAN 2 ports cannot communicate with each other.

Answer 1

Hopefully you have already resolved this, but many managed switches require setting up the ingress and egress behavior of an untagged port separately.

That is, when you assign a port to a specific VLAN — say, VLAN 2 — and set it up into an untagged mode, this only applies to the egress direction — to the VLAN 2 traffic received from the internal switching fabric and destined to be sent out of the port.

The ingress direction — untagged frames that the port receives from an external device — needs to be set up separately. This setting is usually called PVID (Port VLAN ID) and is often found on a separate setup page.

In the usual case, you want the VLAN membership of an untagged port and its PVID to match so that traffic can flow into both directions “the normal way”. Some managed switches indeed make syncing up these values the default behavior when setting up the port’s “native VLAN” (VLAN membership in untagged mode.) There may be some special cases where two-way traffic flow is not wanted, though.

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The user manual for the ZyXEL GS1920-48HP covers these settings in sections 9.5 Configure a Static VLAN (egress setup, where you define which VLANs, if any, output untagged frames from a given port) and 9.6 Configure VLAN Port Settings (ingress setup, and also where the PVID can be defined for each port).

See also:

• What is PVID (Jason Doolittle)
• PVID vs. untagged (Network Engineering Stack Exchange)
• What is the difference between PVID, untagged and tagged (ZyXEL Community)

Answer 2

In ZyXEL switches, when you create the VLANs and give ports access to those VLANs it doesn't automatically assign those ports to the VLANs. I had to find another page to assign the ports to the correct VLANs.