Nortel Networks 43W7774 manual 21CIST Parameter Descriptions

Alteon OS Command Reference

You can view port-specific CIST information, including the following:

„Port number and priority

„Cost

„Link type and Port type

The following table describes the CIST parameters.

Table 4-21CIST Parameter Descriptions

Parameter	Description
CIST Root	The CIST Root shows information about the root bridge for the Common
	Internal Spanning Tree (CIST). Values on this row of information refer to the
	CIST root.
CIST Regional Root	The CIST Regional Root shows information about the root bridge for this
	MSTP region. Values on this row of information refer to the regional root.
Priority (bridge)	The bridge priority parameter controls which bridge on the network will
	become the STP root bridge.
Hello	The hello time parameter specifies, in seconds, how often the root bridge
	transmits a configuration bridge protocol data unit (BPDU). Any bridge that
	is not the root bridge uses the root bridge hello value.
MaxAge	The maximum age parameter specifies, in seconds, the maximum time the
	bridge waits without receiving a configuration bridge protocol data unit
	before it reconfigure the STP network.
FwdDel	The forward delay parameter specifies, in seconds, the amount of time that a
	bridge port has to wait before it changes from learning state to forwarding
	state.
priority (port)	The port priority parameter helps determine which bridge port becomes the
	designated port. In a network topology that has multiple bridge ports con-
	nected to a single segment, the port with the lowest port priority becomes the
	designated port for the segment.
Cost	The port path cost parameter is used to help determine the designated port for
	a segment. Generally speaking, the faster the port, the lower the path cost. A
	setting of 0 indicates that the cost will be set to the appropriate default after
	the link speed has been auto negotiated.
State	The state field shows the current state of the port. The state field can be either
	Discarding (DISC), Learning (LRN), or Forwarding
	(FWD).

92 „ The Information Menu 43W7774, May 2007