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Configuring STP
Prerequisites for Configuring
STP
When you configure VTP, you must configure a trunk port so that the switch can send and receive VTP advertisements
to and from other switches in the domain.
For more information, see
Configuring an Ethernet Interface as a Trunk Port, page 286
Restrictions for Configuring
STP
If you are configuring VTP on a cluster member switch to a VLAN, use the
rcommand
privileged EXEC command to
log in to the member switch.
In VTP versions 1 and 2, when you configure extended-range VLANs on the switch, the switch must be in VTP
transparent mode. VTP version 3 also supports creating extended-range VLANs in client or server mode.
Information About Configuring
STP
This chapter describes how to configure the Spanning Tree Protocol (STP) on port-based VLANs on the switch. The
switch can use either the per-VLAN spanning-tree plus (PVST+) protocol based on the IEEE 802.1D standard and Cisco
proprietary extensions, or the rapid per-VLAN spanning-tree plus (rapid-PVST+) protocol based on the IEEE 802.1w
standard.
STP
STP is a Layer 2 link management protocol that provides path redundancy while preventing loops in the network. For a
Layer 2 Ethernet network to function properly, only one active path can exist between any two stations. Multiple active
paths among end stations cause loops in the network. If a loop exists in the network, end stations might receive duplicate
messages. Switches might also learn end-station MAC addresses on multiple Layer 2 interfaces. These conditions result
in an unstable network. Spanning-tree 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.
The STP uses a spanning-tree algorithm to select one switch of a redundantly connected network as the root of the
spanning tree. The algorithm calculates the best loop-free path through a switched Layer 2 network by assigning a role
to each port based on the role of the port in the active topology:
Root—A forwarding port elected for the spanning-tree topology
Designated—A forwarding port elected for every switched LAN segment
Alternate—A blocked port providing an alternate path to the root bridge in the spanning tree
Backup—A blocked port in a loopback configuration
The switch that has
all
of its ports as the designated role or as the backup role is the root switch. The switch that has at
least
one
of its ports in the designated role is called the designated switch.
Содержание IE 4000
Страница 12: ...8 Configuration Overview Default Settings After Initial Switch Configuration ...
Страница 52: ...48 Configuring Interfaces Monitoring and Maintaining the Interfaces ...
Страница 108: ...104 Configuring Switch Clusters Additional References ...
Страница 128: ...124 Performing Switch Administration Additional References ...
Страница 130: ...126 Configuring PTP ...
Страница 140: ...136 Configuring CIP Additional References ...
Страница 146: ...142 Configuring SDM Templates Configuration Examples for Configuring SDM Templates ...
Страница 192: ...188 Configuring Switch Based Authentication Additional References ...
Страница 244: ...240 Configuring IEEE 802 1x Port Based Authentication Additional References ...
Страница 274: ...270 Configuring SGT Exchange Protocol over TCP SXP and Layer 3 Transport Configuring Cisco TrustSec Caching ...
Страница 298: ...294 Configuring VLANs Additional References ...
Страница 336: ...332 Configuring STP Additional References ...
Страница 408: ...404 Configuring DHCP Additional References ...
Страница 450: ...446 Configuring IGMP Snooping and MVR Additional References ...
Страница 490: ...486 Configuring SPAN and RSPAN Additional References ...
Страница 502: ...498 Configuring Layer 2 NAT ...
Страница 559: ...555 Configuring Network Security with ACLs How to Configure Network Security with ACLs Creating a Numbered Extended ACL ...
Страница 770: ...766 Configuring IPv6 MLD Snooping Related Documents ...
Страница 930: ...926 Configuring IP Unicast Routing Related Documents ...
Страница 956: ...952 Configuring IPv6 Unicast Routing Configuring IPv6 network 2010 AB8 2 48 network 2010 AB8 3 48 exit address family ...
Страница 976: ...972 Configuring Cisco IOS IP SLAs Operations Additional References ...
Страница 978: ...974 Dying Gasp ...
Страница 990: ...986 Configuring Enhanced Object Tracking Monitoring Enhanced Object Tracking ...
Страница 994: ...990 Configuring MODBUS TCP Displaying MODBUS TCP Information ...
Страница 996: ...992 Ethernet CFM ...
Страница 1030: ...1026 Working with the Cisco IOS File System Configuration Files and Software Images Working with Software Images ...
Страница 1066: ...1062 Using an SD Card SD Card Alarms ...