Inter Vlan rule

[White0line]

Hi,

Apologies if this should be in a different forum.

I have a network with multiple Vlans, one of which is Vlan1 (MGT) and one Vlan12 (Core).

There are three external Thunderbolt to ethernet interfaces connected to Vlan12, each with its own Mac/IP (no pass through).

I have a requirement to allow one particular computer to connected to any one of theses interfaces access to Vlan1.

Could someone point me in the right direction for a rule that allows this to happen?

Thanks.