Olicom 8605, 8600 manual Ieee 802.1D Spanning Tree Protocol STP

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IEEE 802.1D Spanning Tree Protocol (STP)

When the IEEE 802.1D Spanning Tree Protocol is active, a port within that domain will require several seconds to make the transition from the blocking state to the forwarding state, when the port is initially activated (e.g. joins an existing ring or activates a dedicated link.) Some client or server applications may attempt to establish session activity during this time, resulting in error messages indicating a connection failure. These applications should be configured to wait at least 30 seconds after the LAN link is active, before attempting to establish session activity. This delay can be reduced by modifying the 802.1D Spanning Tree Protocol default parameters.

If STP is enabled on a dedicated port, and a station is attached to it, it takes at least 30 seconds for the port to transition Down → Listening → Learning → Forwarding.

The IPX client and server stations may have given up before then. And the first many PINGs get lost.

In general, STP should not be enabled on ports, which are intended for dedicated stations. Shared media do not have the same problem, because the port will stay attached to the Hub, even though all stations have closed.

Another reason for not enabling STP on dedicated ports is, that the whole network will go into Topology Change state each time a station opens or closes. This will cause the whole network to use short aging timers, so all address tables will be trashed. The result is a lot of unknown station broadcasts, before the tables converge again.

To disable STP on a port, select the STP Mode Forwarding for this port. Refer to the “STP Mode” parameter on page 104.

CrossFire 8600/8605 Token-Ring Switches v. 1.2, P/N: 710001641 Switch Configuration