C H A P T E R 2 | Using the Intel® NetStructure™ 470T and 470F Switches |
Spanning Tree Protocol and VLANs
The 470 switches support the Spanning Tree Protocol across the entire switch, not across each VLAN. If VLANs create a redundant link between two switches and both of those switches have the Spanning Tree Protocol enabled, one of the VLANs is disabled.
The following diagram shows an example. Both Switch 1 and Switch 2 have two port-based VLANs configured. Crossover cables connect the ENG_VLAN on Switch 1 to ENG_VLAN on and Switch 2. Crossover cables also connect the MKT_VLAN on Switch 1 to the MKT_VLAN on Switch 2. When spanning tree is enabled on both switches, the redundant link between the MKT_VLANs is blocked and those VLANs can no longer communicate. The example below shows 470F switches.
Using the 470 Switch
GARP VLAN Registration Protocol (GVRP)
Because tag-based (IEEE 802.1Q) VLANs can span across the network, it poses a challenge for network administrators to manage changes to the VLAN. The GARP VLAN Registration Protocol (GVRP) provides a dynamic mechanism for switches to share topology information and manage changes with other switches. This saves the network administrator from having to manually propagate VLAN configuration information across switches.
