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I am lost on this, and I could use a bit of help. I have one PC that I want to isolate on my network on its own VLAN.

Here is a rundown of my equipment:

  • Netgear GS752TP Switch
  • Cisco RV120w Router

On the Cisco Router I created VLAN 10 and tagged Port 3 you can see the config here:

enter image description here

It added the VLAN Subnet Table, and it is configured to be the DHCP seen here:

enter image description here

On the Netgear switch, I have configured Port 26 and Port 5 to "Tag" for VLAN 10. (Port 26 goes to Port 3 on my router and Port 5 goes to my PC.)

What I am expecting is my PC on Port 5 to grab an IP address from the DHCP from the router, but instead it is picking up an IP address from my DHCP running on my main network. I am lost....

Here is what I have tried with no success:

  1. Untagged VLAN 10 on Port 3 of the router and Untagged VLAN 10 on the switchports. This Confige will still grab an IP from my main DHCP which is NOT what I want.
  2. I have tried changing PVID to 10 on Switchport 5 & 26. This will NOT grab an IP from the DHCP
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  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can provide and accept your own answer.
    – Ron Maupin ♦
    Feb 19, 2018 at 19:39

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You don't tag VLANs on access interface. You tag VLANs on a trunk interface. The tags are to separate traffic on trunks that carry multiple VLANs. Most end-devices, e.g. PCs don't understand VLAN tags, and they will drop tagged frames as giants.

Simply set any access interfaces in the access VLAN, but do not tag the frames.

If the link between the router and switch is a trunk (traffic for multiple VLANs on the same link), then you tag the frames on the interfaces, otherwise you don't, and you almost never tag the frames on an interface to a PC.

You will need a separate DHCP scope for the network on your new VLAN.

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  • Thanks for the reply. The router has a separate DHCP scope for the network on the new VLAN. I have "Untagged" all ports involved and still it will not grab the DHCP. I have also left the ports "Untagged" and assigned the PVID to 10 with no luck either. I am pretty sure I have tried just about every configuration. I assume the PVID assigns that port to a VLAN?
    – Eric
    Oct 18, 2017 at 19:11
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    Did you exclude VLAN 1 from the Cisco switch interface to the Netgear switch interface VLAN 10 interface to the switch? Your image doesn't show that.
    – Ron Maupin ♦
    Oct 18, 2017 at 23:49
  • Hi Eric, hope you're doing fine. Can you share latest screenshot of your config you tried? (with both ports untagged on switch and router end?) + conf from switch. Is it possible to check CAM table from this switch?
    – Alex
    Oct 18, 2017 at 23:52
  • Can't seem to add a sceen shot but here goes. Router - Port 3 is "Untagged" for VLAN 10 and the other ports are "Excluded" Switch - Port 26 and Port 5 PVID is set to 10 (I assume this puts them on VLAN 10??). They are neither "TAGGED" or "Untagged". This config will NOT grab an IP from the DHCP on the router...
    – Eric
    Oct 19, 2017 at 14:15
  • How did you configure the DHCP scope for the VLAN 10 network? What about VLAN 1? Does it show excluded for port 3?
    – Ron Maupin ♦
    Oct 19, 2017 at 21:45

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