Cabletron Systems SSIM-H2-02 manual Introduction, Ports, Port Groups and VLANs

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Introduction

Each SSIM-H2-02 has two 100 Mbps Fast Ethernet ports. In the console configuration, port numbers are used to refer to ports, with ordinary Token Ring ports numbered 1 to 20. If a module is inserted into the left expansion slot, the TS ports are numbered 21 and 22. If a module is inserted into the right expansion slot, the TS ports are numbered 25 and 26. The number of modules in a stack is limited only by the number of available slots in the stack.

The TS ports are configured much like ordinary Token Ring ports, and generally appear in all tables where ordinary Token Ring ports appear.

Ports, Port Groups and VLANs

This section briefly describes the VLAN concept and switching modes of the SmartStack STS16-20RM Switch. For more detailed information about these subjects, see the SmartStack STS16-20RM/STS16-20FRM Token Ring Switch Installation and User Guide.

The switch supports up to 63 VLANs. A VLAN forms a single bridged domain and the visibility of MAC addresses, bridge and ring numbers as well as the scope of broadcast frames are limited to the VLAN in which they originate. Frames must be routed to move between VLANs.

A VLAN consists of a number of port groups called CRFs (Concentrator Relay Functions). A CRF is conceptually equal to a ring. If a VLAN contains two or more CRFs they are conceptually connected by a multiport bridge called a BRF (Bridge Relay Function).

The BRF performs either source-route bridging (SRB) or source-route transparent switching (SRT) between CRFs depending on the CRF configuration. CRFs configured for SRT switching form an SRT domain in which source-routed frames are source routed and non-source-routed frames are transparently switched.

Each ordinary Token Ring port is assigned to a specific CRF, which also determines to which VLAN it belongs.

In the default configuration, all ordinary Token Ring ports are assigned to the trcrf- default CRF, which belongs to the trbrf-default BRF. The only limitations to this are that the names cannot be changed, the parent BRF of the default CRF cannot be changed and other CRFs cannot be assigned to the trbrf-default BRF.

SSIM-H2-02 Fast Ethernet - Translational Switch SmartStack Interface Module Installation and User Guide Configuration