CANOGA PERKINS CanogaOS Configuration Guide - Manual (Page 43)

CanogaOS Configuration Guide
Proprietary & Confidential Canoga Perkins Metro Ethernet Switches Page 43 of 350
7 Configuring RSTP/STP
7.1 RSTP/STP Configuration
Spanning Tree Protocol (STP, IEEE 802.1D-1998) is a Layer 2 link-management protocol that
provides path redundancy while preventing undesirable loops in the network. For a Layer 2
Ethernet network to function properly, only one active path can exist between any two stations.
STP operation is transparent to end stations, which cannot detect whether they are connected to a
single LAN segment or a switched LAN of multiple segments.
Rapid Spanning Tree Protocol (RSTP, IEEE 802.1w) can be seen as an evolution of the 802.1D
standard more than a revolution. The 802.1D terminology remains primarily the same. Most
parameters have been left unchanged so users familiar with 802.1D can rapidly configure the
new protocol comfortably. RSTP was developed to decrease the recovery time of redundant
paths in Layer 2 networks as compared to the IEEE 802.1d Spanning Tree Protocol (STP) while
continuing to reduce the impact of accidental network loops. RSTP can reduce the spanning tree
convergence time to 5 seconds or less to establish a network path and reduce network downtime.
7.1.1 References
IEEE 802.1D (2004)
RFC 4318
RFC 4188 Bridge MIB
7.1.2 Topology
Bridge 2
Bridge 3 Bridge 4
Bridge 1
eth-0-3 eth-0-3
eth-0-4 eth-0-4
eth-0-3 eth-0-3
eth-0-3 eth-0-4
eth-0-1 eth-0-2
eth-0-1
eth-0-1
eth-0-2
eth-0-2 eth-0-1 eth-0-2
8192
12288
16384 32768