The All-New Switch Book: The Complete Guide to LAN Switching Technology, Second Edition

5.8. Up a Tree Without a Protocol?

What if (heaven forbid!) someone built a bridge that did not include support for the STP or any other loop resolution algorithm? Would the Catenet Police arrest the person and confiscate the equipment? Would the person be banned for life from IEEE meetings?^[] More important, would it affect users?

^[] If so, we will get Rich to build a bridge like this immediately!

5.8.1. Why Would Anyone Do This?

What would be the benefit to building a bridge or switch with no support for the STP? There are three reasons:

• Cost

• Cost

• Cost

In addition, it may be possible to save money by not including STP support. At the low end of the marketplace, every penny spent on the product weighs against the product competitively. The idea behind eliminating STP support is to avoid having to put any kind of control processor within the device. If a switch is built that does not require a processor for the data forwarding or lookup functions (e.g., it uses a finite-state machine implemented completely in hardware), then adding a processor simply to execute the STP constitutes an incremental expense.

Such a device would clearly be a "no-frills" switch. In addition to not supporting the STP, it could not support any standard network management protocols (for example, SNMP), Link Aggregation Control, and so on. Because of this, such devices are sometimes referred to as unmanaged switches.

For better or for worse, there is a marketplace for such products, and they do exist. They ...