3Com WX1200 3CRWX120695A Managing STP Fast, Convergence, Features, Changing the STP Maximum Age

358CHAPTER 17: CONFIGURING AND MANAGING SPANNING TREE PROTOCOL

	The all option applies the change to all VLANs. Alternatively, specify an
	individual VLAN.
	To change the forwarding delay on VLAN pink to 20 seconds, type the
	following command:
	WX1200# set spantree fwddelay 20 vlan pink
	success: change accepted.
	Changing the STP Maximum Age
	To change the maximum age, use the following command:
	set spantree maxage aging-time{all vlan vlan-id}
	Specify an age from 6 through 40 seconds. The default is 20 seconds.
	The all option applies the change to all VLANs. Alternatively, specify an
	individual VLAN.
	To change the maximum acceptable age for root bridge hello packets on
	all VLANs to 15 seconds, type the following command:
	WX1200# set spantree maxage 15 all
	success: change accepted.
Configuring and	The standard STP timers delay traffic forwarding briefly after a topology
Managing STP Fast	change. The time a port takes to change from the listening state to the
Convergence	learning state or from the learning state to the forwarding state is called
Features	the forwarding delay. In some configurations, this delay is unnecessary.
	The WX switch provides the following fast convergence features to
	bypass the forwarding delay:
	„	Port fast
	„	Backbone fast
	„	Uplink fast
Port Fast	Port fast convergence bypasses both the listening and learning stages and
Convergence	immediately places a port in the forwarding state. You can use port fast
	convergence on ports that are directly connected to servers, hosts, or
	other MAC stations.

Do not use port fast convergence on ports connected to other bridges.