From: johngibson1541@yahoo.com
Date: Tue Dec 26 2006 - 22:24:36 ART
John,
I got this from the Cat 3550 config guide...it's one switch that will allow you to manually prune vlan 1 from a trunk.
To reduce the risk of spanning-tree loops or storms, you can disable VLAN 1 on any individual VLAN trunk port by removing VLAN 1 from the allowed list. This is known as VLAN 1 minimization. VLAN 1 minimization disables VLAN 1 (the default VLAN on all Cisco switch trunk ports) on an individual VLAN trunk link. As a result, no user traffic, including spanning-tree advertisements, is sent or received on VLAN 1.
When you remove VLAN 1 from a trunk port, the interface continues to send and receive management traffic, for example, Cisco Discovery Protocol (CDP), Port Aggregation Protocol (PAgP), Link Aggregation Control Protocol (LACP), Dynamic Trunking Protocol (DTP), and VLAN Trunking Protocol (VTP) in VLAN 1.
To answer your question about BPDUs though...it depends on your STP implementation. For example, if you are running PVST+ and have configured a vlan other than vlan 1 to be your native vlan, then vlan 1 is not needed on the trunks. This design is actually recommended. You obviously wouldn't want to do this if you are using vlan 1 as your native vlan, the dot1q default, so be careful.
Ronnie
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