guest network using tagged VLANs

[Steve Sapovits]

On 1/12/2020 5:56 PM, Steve Sapovits wrote:
>
> You would use a switch that allows a single port to be assigned to 
> both VLANs, then run that cable to a NIC on the DHCP server. Then 
> configure the DHCP server to listen on both VLAN subnets. From my 
> understanding of DHCP, that should be enough for the client to 
> discover the DHCP server to start the transaction.  So it would seem 
> to come down to whether ISC DHCP can return an address that's outside 
> of the subnet it's listening on.  My understanding is that a trunk 
> port (one assigned to all VLANs) assigns the right VLAN ID to any 
> untagged packets.   So the right VLAN ID should be added once the 
> client gets its IP address and that flows back to the trunk port on 
> the VLAN switch.
>
> Caveat here is I'm really not an expert ...

Reading more about this, I think I'm wrong.  If a packet hits a trunk 
port (Cisco anyway) with no tag, it gets a default tag.

I don't think a trunk port is intended for what I was thinking.

I don't think you can connect anything not sending tagged VLAN packets 
to a trunk port.  So I think that brings us back to your original point 
-- make sure the WAP can do the tagging.

Otherwise, it would seem to require two WAPs.

-- 
Steve Sapovits
steves06 at comcast.net