I have a Catalyst switch that doesn't support PVLAN trunks (Sup4, 4500, 12.2(54)S). I have multiple other Catalyst switches, 3750 metro, that do.

Am I correct in assuming that because the C4500 does not support PVLAN trunks with that Supervisor, that a normal trunk port would not work for the 3750s to share a private VLAN with the 4500?

The desired scenario is that the 4500 hosts primary VLAN 500 and isolated vlans 501,502 with 501,502 residing on other 3750s in the network. I assume that in order to achieve the desired config, I have to have the 3750 promiscuous ports connected to access ports on the 4500. Is this correct?

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1 Answer 1


A promiscuous trunk on the 3750 toward the 4500 is what you need to go across a non-PVLAN-aware switch and keep security intact.

See Promiscuous PVLAN Trunk Ports

  • The 4500 is PVLAN-aware. I assume what "no PVLAN trunks" means is that the promiscuous and isolated special-type trunks aren't available. I'm looking for verification.
    – Arima
    Jul 10, 2013 at 13:18

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