Private VLAN between Cisco switch and other vendor switch or firewall

Unanswered Question
Feb 5th, 2008

Can anyone plz help me in understanding the tagging of private vlan on trunk ports.

I have a trunk link between nokia firewall and cisco 3750 switch, there are some servers in private vlan in the switch and need to communicate to a server behind the firewall, can just a trunk link between the firewall and the switch suffice (consider the firewall in not blocking any traffic)

I have this problem too.
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aghaznavi Mon, 02/11/2008 - 08:02

Most non-Cisco 802.1q switches maintain only a single instance of spanning tree, known as Mono Spanning Tree (MST), that defines the spanning-tree topology for all VLANs. When a Cisco switch is connected to a non-Cisco switch through an 802.1q trunk, the MST of the non-Cisco switch and the native VLAN spanning tree of the Cisco switch combine in order to form a single spanning tree topology, known as the Common Spanning Tree (CST).

tmsundar81 Mon, 02/11/2008 - 08:38

Thanks for the info but i need to understand the tagging between a cisco switch and a non cisco switch...say i have a private vlan on a cisco switch and i am connecting to a non cisco switch (nokia fw) and i ahave a trunk link between (only trunk link)between such case can a reach the private vlan from nokia fw via the trunk link

or do i need to have a seperate link for the private vlan between cisco switch and nokia fw (promiscuous port on cisco switch end)


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