VLAN from Smart switch to unmanged switch


I configured Crap network Vlan 70 and goes to CISCO Switch then goes to TP Link SG108E, then I configured 802.1Q for VLAN70 to port 5 which goes to Dlink unmanaged switch.

There are 3 devices connected and only one takes ipaddress from Crap Network, rest have not taken ip address. Is there anything I am missing.


What’s the config on the interface? Also, do you have a DHCP server on VLAN70?

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Yes PFsense is configured for DHCP Server, one device could get ip address.

On the port 5 I configured Vlan 70 as untagged and Port 1 as tagged (which is trunk port). On Cisco its configured as trunk port on which TP Link SG108E is connected.

I would configure the port for the TP link switch to access vlan 70.

Hey I have no clue how to exactly setup your switch, however from what I understand – one a singe port only one VLAN can be untagged and the rest need to be tagged.

I’m looking at your diagram – at the bottom three lines
VLAN 70 is associated with ports 1 and 5. Its untagged on Port 5 and Tagged on Port 1

VLAN 10 is associated with Ports 1, 3, and 4. Untagged on Ports 3 and 4 and Tagged on Port 1
VLAN1 (default VLAN) has port members 1-8. However I think you have all those designated as Untagged for VLAN 1. I’m not sure how you want to configure your network and could be totally reading the graph wrong, however I think
VLAN 1 needs to be Tagged for ports 3,4,5 and Untagged for ports 1,2,6,7,8 or just have VLAN 1 be only a member of ports 1,2,6,7,8.

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In TP-Link SG108E, Vlan1 entry is by default and you cant change or delete that.

Tom has a video on this and explains about vlan1 https://youtu.be/5ohLAFHnOHg

This is a Smart Switch so things are littile different, and I was able to successfully configure and get Vlan 10 and Vlan 70 talk to there DHCP server.

My issue is on port 5 I connect unmannged switch which is connected to my 2 Solar Inverter and one Controller and needs to be on Vlan 70 network. But only one device i.e controller is able to get ipaddress but 2 Solar Inverter does not get ipaddress.

As I understand till the packet reaches TP-Link they can remain untaged (unmanaged) and then when TP-Link sends packets to trunk port would add Vlan ID, in that case It should have worked.

I will try to add another unmanaged switch to port 3 and see if even that behaves like that.

A trunk port will only tag traffic if you setup a native VLAN for it. Whenever you have an unmanaged switch (no VLAN assignments), then all the devices plugged into that switch will be devices on the same network/VLAN. That VLAN is defined by the config you put on the uplink port. One thing I didn’t mention is STP though. There is a good chance that the unmanaged switch is sending BPDUs via the uplink port so setting up a trunk port with a native VLAN of VLAN 70 is probably the best way to get this working. You could also filter BPDUs on an access port, but either way should work.


You need to set the PVID (that’s on a different screen) for port 5 of the TP-Link switch to 70 (and not tagged). Everything connected to the “dumb” switch will be on VLAN 70.

For others reading this thread who may be using a Netgate box, their built-in switches need to also have the PVID set for access ports. I just set up an SG-3100, and the ports are set to VLAN 1 (port 1), PVID 40 (port 2), and trunk (all VLANs assigned) for ports 3 and 4.


I will try to do what you said and see if it works :slight_smile:

I did that setting as @LTS_Tom suggested in his video.

Finally got it working, I disconnected unmanaged switch and reconnected it back that for ip address to one more device but one left out.

Then I noticed in firewall that the second Solar Inverter was using old ip address, then I contacted Solar Installer he reset the network connection that got it working. He further stated that this two inverter are connected in daisy chain. I was wondering if that could have been the probable cause.

All in all got things working, Thanks a lot for support :slight_smile:

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