3Com 3500 manual Bridge spanningTree stpMaxAge

262CHAPTER 9: BRIDGE-WIDE PARAMETERS

bridge spanningTree stpMaxAge

✓3500

✓9000

✓9400

✓3900

✓9300

Determines when the stored CPDU configuration message is discarded from the bridge’s memory if the bridge is the root bridge. The current value is shown in the bridgeMaxAge field of the bridge display.

Valid Minimum Abbreviation

b sp stpm

Important Considerations

■If the value is too small, the STP may reconfigure the topology too often, causing temporary loss of connectivity in the network.

■If the value is too large, the network may take longer than necessary to adjust to a new STP configuration after a topology change such as the restarting of a bridge.

■A conservative value assumes a delay variance of 2 seconds per hop. The recommended and default value is 20 seconds.

■Although the possible range for stpMaxAge is 6 – 40, the available range is constrained by the following inequalities:

■2 x (stpForwardDelay - 1 second) >= stpMaxAge

■stpMaxAge >= 2 x (stpHelloTime + 1 second)

Options

Prompt	Description	Possible Values	[Default]
STP max age	Value (in seconds) when the	6 – 40 seconds	20 (factory
	stored configuration message		default), or
	information is deemed too old		current value
	and is discarded