Hi,

I just wanted to run this by you guys to see if it's something that anyone has come across before.

DrayTek 2862 setup with 2 port based VLANs (1 and 2). I've just purchased a new managed switch, like most of us I am trying to save some energy so I am consolidating separate switches into one. The topology is really simple, the switch (TP-Link TP-SG116E) has half of it's ports set to VLAN1 and the other half to VLAN2. When I connect the router uplink for VLAN1 the everything is good and the network is running well. I then plug in the router uplink for VLAN2 and the problems start. PCs on VLAN2 have 60-70% packet loss, pinging the routers VLAN2 interface results in lots of time outs. The VLAN1 PCs don't suffer quite as badly but I am getting packet loss, enough to kill VoIP calls. When I pull the VLAN2 uplink everything returns to normal. The symptoms remind me of a network loop. My gut feel is there is something broken in the switch and I have already engaged TP support but if there is anything on the DrayTek side worth checking?

Thanks
Rob

It does sound like a loop - presumably in the TP-Link, since it didn't happen when you had two separate switches...

But having two devices connected by two links, sounds like an accident waiting to happen :wink: (it's never ended well, when I've done it :oops: )

Why not switch to using tagged Vlans, instead of Port-based? In this configuration, it would actually be simpler (only one interconnection). This assumes that the TP-link can do the "tag on ingress", "de-tag on egress" trick, for the connected clients benefit.

Yeah, tagging is my next option but I have a couple of dumb switches (which is the reason I went port based originally) that'll I need to upgrade before that happens.

Cheers

One for the knowledgebase.

I've moved over using 802.1Q VLANs instead of port based. After a lot of faffing around I found the solution, so just in case someone else comes across this thread later.

- The default VLAN on the switch must not be used for tagging, this appears to confuse the DrayTek (or its doing something odd at the switch, either way don't use it)
- Create new VLANs with new VID on the 802.1Q VLAN page, here I only added the member ports I wanted for each VLAN
- One the 802.1Q PVID Setting screen change the port membership to the right VLANs
- Now the bit that caused me so much grief, go back to the 802.1Q VLAN Page and add Port 1 to the new VLANS but make sure it's a tagged port.
- What you should have now is at least 2 VLANS, the default on port 1 only and untagged (you can inlcude other ports but I wanted this screen to reflect the PVID settings screen), the second is your new VLAN which will have all the member ports assigned and also port 1 as a tagged port.
- Now you just need to pop down to the DrayTek and configure the VLANs to match the switch configuration.

Cheers
Rob