VLAN Tagging Virtual Interface

QNAP NAS solution for server virtualization and clustering/HA/FT
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VLAN Tagging Virtual Interface

Post by RHLinux » Sun May 03, 2020 1:44 pm

Now that QNAP have updated the firmware to include VLAN tagging for a virtual interface, they didn't quite implement it correctly.

You can now create VLAN and connect them to virtual switches, but the main untagged interface disappears and can't be connected to the virtual switches.


Untagged Interface 1 - VLAN1
Tagged Interface 1 - VLAN10, VLAN20, VLAN30

In the network and virtual switch, only the Tagged Interface appears and you can't connect the untagged interface 1 (VLAN1) to any virtual switches. The reason you might want to do this is to have the untagged interface available for the rest of the QNAP services (sharing, etc...) an also have the ability to use Virtualization station able to use the untagged lan interface, but only the tagged vlans are available.

Why they implemented VLANs like this I have no idea. As soon as you create a vlan in the network and virtual switch, the main interface disappears and you can no longer connect it to any virtual switches.

I have sent QNAP a but report and ticket, but they regard this as a "feature". Why they regard this as a feature is beyond my comprehension. It's basic networking 101 to have the ability to use the untagged interface... It's how network switches work!! Untagged on the base interface port and trunked vlans.

I have no idea when and if QNAP will ever get around to fixing this issue, it is not a feature and it's needed to implement vlans properly on virtual switches.

What are your thoughts and is there a way round this "feature" ;)


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Re: VLAN Tagging Virtual Interface

Post by zqush » Sun Jun 28, 2020 1:43 pm

I'm having similar troubles with this. The minute I setup the VLAN on Adapter 2, everything went wrong. The Virtual Adapters of my Containers disappeared and containers fail to start with the following error.

Background task error for create openhab-1: 500 Server Error: Internal Server Error ("IpamDriver.RequestAddress: Qnet IPAM cannot discover any DHCP server")

What I want is to have some containers to connect to my main LAN (untagged) and some containers (OpenHAB to be specific) to use the VLAN 44 which is the VLAN I use for all home automation devices.

Their implementation seems to be broken.

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Re: VLAN Tagging Virtual Interface

Post by hellokaiser » Tue Jun 30, 2020 5:10 am

Similar, but slightly inversed problem here: The physical Adapter (trunked) are set to obtain their IP address via an external DHCP server and the same for DNS. When I add a VLAN (Virtual ) to the trunked Adapter 1+2 and configure it to obtain IPv4/6 and DNS automatically, then I can see the same device two times in the managed switch: One for each interface (MAC address helps identifying it). One device is in the untagged default VLAN1 and the second one is in the tagged VLAN.
The good thing is: If I now add a virtual switch (again: DHCP client, obtain DNS autom.) and attach a virtual adapter, I might be able to add whatever is running on some VM or container and map it to the network on it's own subnet/ attach it to a VLAN and represent it like any physical device to the outside world.
Is this how VLAN segregation works? Not really…

EDIT The virtual adapter has taken down part of my routing. I had to remove it. The feature simply is not ready to get used. That's an alpha version in production.

EDIT 2 While I set everything to "auto obtain DHCP/DNS", my switch detected a rogue DHCP server. And that one came exactly from the tagged VLANs subnet .1-address on top of the Adapters. Nice. Not.

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