Is it possible to assign a switch port to a VLAN based on the fact that the host IP address is on a certain subnet? I have found the following references from HP and Netgear, but I have been unable to find any such functionality for Cisco. Please note that this is only academic at this time.

Netgear Link

In an IP subnet–based VLAN, all the end workstations in an IP subnet are assigned to the same VLAN. In this VLAN, users can move their workstations without reconfiguring their network addresses. IP subnet VLANs are based on Layer 3 information from packet headers. The switch makes use of the network-layer address (for example, the subnet address for TCP/IP networks) in determining VLAN membership. If a packet is untagged or priority tagged, the switch associates the packet with any matching IP subnet classification.

HP Link

In this method, packets are assigned to VLANs based on their source IP addresses and subnet masks. A port configured with IP Subnet-based VLANs assigns a received untagged packet to a VLAN based on the source address of the packet. Use this feature when packets from an IP Subnet or IP address must be transmitted in a VLAN. This feature is available only on hybrid ports, and it processes only untagged packets.


i think you mean dynamic vlan membership , you can find detailed information about it on this link http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/12-2/25ew/configuration/guide/conf/vmps.html


Short answer: Impossible.

I'm pasting the answer from here:

First of all it is not possible without assigning the ports to vlans. Any computer connected to any switch port need to be in some vlan.

Now it depends on you that you want to configure static vlan on ports or dynamic vlans which is called VMPS.

What you want is possible that any pc connected to any port will request from the VMPS server to automatically get binded to vlan and port and you will have to create interface vlan 100 and interface vlan 200 on any layer 3 switch with different subnets.

Also to conf VMPS server you have to have high end switch.

  • why do you say t's impossible while providing info on how to do it? – JFL Sep 24 '15 at 7:18
  • Did you read the answer completely? It's impossible in Cisco to do subnet-based VLAN assignment. The info is about VMPS which is something "similar" but yet not what the questioner wants. VMPS is an option to dynamically assign VLAN, but not based on the packet received on the switchport from the host? – moghaddas Sep 24 '15 at 10:20

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