HP 2500 manual Problems Related to Spanning-Tree Protocol STP, Stacking-Related Problems

Troubleshooting

Troubleshooting

Unusual Network Activity

	Problems Related to Spanning-Tree Protocol (STP)
C a u t i o n	If you enable STP, it is recommended that you leave the remainder of the STP
	parameter settings at their default values until you have had an opportunity
	to evaluate STP performance in your network. Because incorrect STP settings
	can adversely affect network performance, you should avoid making changes
	without having a strong understanding of how STP operates. To learn the
	details of STP operation, refer to the IEEE 802.1d standard.
	Broadcast Storms Appearing in the Network. This can occur when
	there are physical loops (redundant links) in the topology.Where this exists,
	you should enable STP on all bridging devices in the topology in order for the
	loop to be detected.
	STP Blocks a Link in a VLAN Even Though There Are No Redundant
	Links in that VLAN. In 802.1Q-compliant switches such as the Switch 2512
	and Switch 2524, STP blocks redundant physical links even if they are in
	separate VLANs. A solution is to use only one, multiple-VLAN (tagged) link
	between the devices. Also, if ports are available, you can improve the band-
	width in this situation by using a port trunk. See "STP Operation with 802.1Q
	VLANs" on page 9-110.
	Stacking-Related Problems
	The Stack Commander Cannot Locate any Candidates. Stacking oper-
	ates on the primary VLAN, which in the default configuration is the
	DEFAULT_VLAN. However, if another VLAN has been configured as the
	primary VLAN, and the Commander is not on the primary VLAN, then the
	Commander will not detect Candidates on the primary VLAN.
	Timep or Gateway Problems
	The Switch Cannot Find the Timep Server or the Configured
	Gateway . Timep and Gateway access are through the primary VLAN, which
	in the default configuration is the DEFAULT_VLAN. If the primary VLAN has
	been moved to another VLAN, it may be disabled or does not have ports
	assigned to it.

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