Patching multiple untagged VLANs for DHCP - HP Procurve 2510G-25

Posted on 2012-08-24
Last Modified: 2013-01-15
First allow me to explain the desired operation. I wish to have two isolated networks in the same switch.  These will be domain and testnet.  Each is an untagged vlan.  I wish to be able to jumper a patch cable between domain and testnet, when the testnet vlan is not in use for testing and system configuration.  The result would be the ports of the testnet vlan acting with DHCP and domain access. The reason for this is so that I can isolate my laptop just by unplugged the patch between domain and testnet.

The current issue is that when configured in this way dhcp does not work on the testnet vlan, when the patch is in place.  Isolation works properly.

My questions are why does DHCP not work across the untagged vlans, when they are patched together, and is this a valid possible configuration or is there a better way to handle this?

Yes I am aware that I could just move the cable for my laptop between vlans, and yes I know I can switch my port's vlan in the software. These are not desired methods and I would like it to work as described.
Question by:cpoint-service
    1 Comment
    LVL 17

    Accepted Solution

    I assume it's because the MAC of your laptop would be both on untagged port_X on vlan_test and untagged port_Y on vlan_domain, and a MAC can't exist on two ports on one switch.
    Although as I know, there's no exact specification for switches on how to handle the same MAC address on multiple VLANs.


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