Enterasys Networks 2H253, 2E253, 2H252, 2H258 manual Generic Attribute Registration Protocol Garp

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Generic Attribute Registration Protocol (GARP)

This appendix describes the switch operation when its ports are operating under the Generic Attribute Registration Protocol (GARP) application – GARP VLAN Registration Protocol (GVRP).

NOTE: There is a global setting for GVRP that is enabled by default. Access to these settings is only available through a MIB.

A.1 OVERVIEW

The process of the forwarding decision and tagging frames is the same as for 802.1Q as described in Chapter 12. However, the GVRP protocol frames will not have a tag even when transmitted out an 802.1Q Trunk Port.

The purpose of GVRP is to dynamically create VLANs across a switched network. When a VLAN is declared, the information is transmitted out GVRP configured ports on the switch in a GARP formatted frame using the GVRP multicast MAC address. A switch that receives this frame, examines the frame, and extracts the VLAN IDs. GVRP then creates the VLANs and adds the receiving port to its tagged member list for the extracted VLAN ID(s). The information is then transmitted out the other GVRP configured ports of the switch. Figure A-1shows an example of how VLAN blue from end station A would be propagated across a switch network.

Generic Attribute Registration Protocol (GARP) A-1