native vlan vs vlan 1

[Peter Handke]

Hi

I have a few switches ( let's say 3550/3560) with all port as a trunk. On every port i have different native vlan, other than 1. What tag, on trunk ports,  switch uses for transmit normal STP frames ? or VTP, LACP, PaGP ? It's vlan 1 ? i have to have vlan 1 on my trunks as tagged ? I'm just wondering about that. Thanks for explanation.

[Reza Sharifi]

Vlan 1 can not be deleted.  It can only be disabled, but even when it is disabled, it continues to send and receiver control protocols such as CDP, VTP, PAGP, etc...

HTH

[milan.kulik]

Hi,

here you can read some more details:

http://www.cisco.com/en/US/customer/products/hw/switches/ps708/products_white_paper09186a00801b49a4.shtml#pre6

http://www.cisco.com/image/gif/paws/24330/185.pdf

HTH,

Milan

[milan.kulik]

Hi,

here you can read some more details:

http://www.cisco.com/en/US/customer/products/hw/switches/ps708/products_white_paper09186a00801b49a4.shtml#pre6

http://www.cisco.com/image/gif/paws/24330/185.pdf

HTH,

Milan

[krahmani323]

Hello Peter, Reza, Milan

Thanks for your inputs. Allow me also to add this link regarding specifities between STP IEEE/[R]PVST+ in regards to the native vlan (VLAN1 or not).

http://www.cisco.com/en/US/tech/tk389/tk621/technologies_tech_note09186a00801d11a0.shtml#topic1

This list shows how (R)PVST+ interoperates with IEEE 802.1Q or IEEE 802.1D =>

If the Native VLAN on an IEEE 802.1Q trunk is VLAN 1:

• VLAN 1 STP BPDUs are sent to the IEEE STP MAC address (0180.c200.0000), untagged.
• VLAN 1 STP BPDUs are also sent to the PVST+ MAC address, untagged.
• Non-VLAN 1 STP BPDUs are sent to the PVST+ MAC address (also called the Shared Spanning Tree Protocol [SSTP] MAC address, 0100.0ccc.cccd), tagged with a corresponding IEEE 802.1Q VLAN tag.

If the Native VLAN on an IEEE 802.1Q trunk is not VLAN 1:

• VLAN 1 STP BPDUs are sent to the PVST+ MAC address, tagged with a corresponding IEEE 802.1Q VLAN tag.
• VLAN 1 STP BPDUs are also sent to the IEEE STP MAC address on the Native VLAN of the IEEE 802.1Q trunk, untagged.
• Non-VLAN 1 STP BPDUs are sent to the PVST+ MAC address, tagged with a corresponding IEEE 802.1Q VLAN tag.Note: Native VLAN STP BPDUs are sent untagged.

Best regards.

Karim