Moxa Technologies EDS-726 Differences between Rstp and STP, STP Calculation, STP Configuration

Page 42

EDS-726 Series User’s Manual

Featured Functions

STP Calculation

The first step of the STP process is to perform calculations. During this stage, each bridge on the network transmits BPDUs. The following items will be calculated:

yWhich bridge should be the Root Bridge. The Root Bridge is the central reference point from which the network is configured.

yThe Root Path Costs for each bridge. This is the cost of the paths from each bridge to the Root Bridge.

yThe identity of each bridge’s Root Port. The Root Port is the port on the bridge that connects to the Root Bridge via the most efficient path. In other words, the port connected to the Root Bridge via the path with the lowest Root Path Cost. The Root Bridge, however, does not have a Root Port.

yThe identity of the Designated Bridge for each LAN segment. The Designated Bridge is the bridge with the lowest Root Path Cost from that segment. If several bridges have the same Root Path Cost, the one with the lowest Bridge Identifier becomes the Designated Bridge. Traffic transmitted in the direction of the Root Bridge will flow through the Designated Bridge. The port on this bridge that connects to the segment is called the Designated Bridge Port.

STP Configuration

After all the bridges on the network agree on the identity of the Root Bridge, and all other relevant parameters have been established, each bridge is configured to forward traffic only between its Root Port and the Designated Bridge Ports for the respective network segments. All other ports are blocked, which means that they will not be allowed to receive or forward traffic.

STP Reconfiguration

Once the network topology has stabilized, each bridge listens for Hello BPDUs transmitted from the Root Bridge at regular intervals. If a bridge does not receive a Hello BPDU after a certain interval (the Max Age time), the bridge assumes that the Root Bridge, or a link between itself and the Root Bridge, has gone down. This will trigger the bridge to reconfigure the network to account for the change. If you have configured an SNMP trap destination, when the topology of your network changes, the first bridge to detect the change sends out an SNMP trap.

Differences between RSTP and STP

RSTP is similar to STP, but includes additional information in the BPDUs that allow each bridge to confirm that it has taken action to prevent loops from forming when it decides to enable a link to a neighboring bridge. Adjacent bridges connected via point-to-point links will be able to enable a link without waiting to ensure that all other bridges in the network have had time to react to the change. The main benefit of RSTP is that the configuration decision is made locally rather than network-wide, allowing RSTP can carry out automatic configuration and restore a link faster than STP.

3-27

Page 41 Page 43
Image 42
Page 41 Page 43
Contents Moxa EtherDevice Switch EDS-726 Series User’s Manual First Edition, JulyCopyright Notice TrademarksDisclaimer Table of Contents Chapter EDS Configurator GUI Introduction Overview Package ChecklistFeatures Industrial Networking CapabilityUseful Utility and Remote Configuration Recommended Software and AccessoriesGetting Started RS-232 Console Configuration 115200, None, 8, 1, VT100 Connection CautionEDS-726 Series User’s Manual Key Function Configuration by Telnet Console Configuration by Web Browser EDS-726 Series User’s Manual Disabling Telnet and Browser Access Featured Functions Configuring Basic Settings System IdentificationSwitch Location PasswordSwitch Name Switch DescriptionPassword AccountAny host can access the EDS-726 Accessible IPAny host on a specific subnetwork can access the EDS-726 Allowable Hosts Input formatDescription EnablePort NameFDX Flow Control NetworkPort Transmission Speed Port TypeSwitch Subnet Mask Auto IP ConfigurationSwitch IP Address Default GatewayCurrent Date TimeCurrent Time System Up TimeSystem File Update-By Remote Tftp System File Update-By Local Import/Export Using Port Trunking System File Update-By CF CardFactory Default Port Trunking Concept Configuring Port Trunking Trunk Type Setting DescriptionTrunk Group Maximum of 4 trunk groups Member Ports/Available PortsConfiguring Snmp SnmpV1, V2c Read Community Snmp Read/Write SettingsSnmp Versions V1, V2c Write/Read CommunityTrap Settings Trap Server IP/NamePrivate MIB information Using Communication RedundancySwitch Object ID Gigabit Ethernet Redundant Ring Capability 300 msInitial Setup Turbo Ring ConceptWhen the number of EDS-726 units in the Turbo Ring is even Ring Coupling Configuring Turbo Ring STP/RSTP Concept What is STP? How STP Works STP RequirementsPort Speed Path Cost 802.1D Edition 802.1w-2001 Differences between Rstp and STP STP ConfigurationSTP Reconfiguration STP CalculationUsing STP on a Network with Multiple VLANs STP ExampleConfiguring STP/RSTP Protocol of Redundancy Forwarding DelayRoot/Not Root Bridge priorityPort Priority Configuration Limits of RSTP/STPEnable STP per Port Port CostTraffic Prioritization Concept Using Traffic PrioritizationWhat is Traffic Prioritization? How Traffic Prioritization WorksDifferentiated Services DiffServ Traffic Marking Ieee 802.1p Priority Level Ieee 802.1D Traffic TypeTraffic Prioritization Configuring Traffic Prioritization QoS ClassificationTraffic Queues Inspect TOS Default Port PriorityQueuing Mechanism Inspect COSSetting Description Factory CoS MappingTOS/DiffServ Mapping Using Virtual LAN What is a VLAN?Virtual LAN Vlan Concept Managing a Vlan VLANs and Moxa EtherDevice SwitchBenefits of VLANs Communication Between VLANsSample Applications of VLANs using Moxa EDS-726 HUBConfiguring 802.1Q Vlan Vlan Port SettingsPort Fixed Vlan List Tagged Management Vlan IDPort Pvid Port Forbidden Vlan ListConcept of Multicast Filtering Using Multicast FilteringWhat is an IP Multicast? Benefits of MulticastMulticast Filtering Network without multicast filteringQuery Mode Multicast Filtering and Moxa EtherDevice SwitchIgmp Internet Group Management Protocol Snooping Mode Igmp Multicast FilteringStatic Multicast MAC Configuring Igmp SnoopingIgmp Snooping Settings Enabling Multicast FilteringQuerier Igmp SnoopingStatic Multicast Router Port Igmp TableNone Add Static Multicast MACAdd New Static Multicast Address to the List Join PortGmrp enable Setting Description Factory Default Configuring GmrpPort Setting Description Factory Default Port Mode Setting Description Factory DefaultGmrp Table Using Bandwidth ManagementConfiguring Bandwidth Management Broadcast Storm ProtectionIeee Using Port Access ControlTraffic Rate Limiting Settings Static Port LockMessage Exchange Configuring Ieee 802.1XServer Port Database OptionRadius Server Shared Key802.1X Re-Authentication Local User Database Setup802.1X Re-Authentication Local User Database Setup Static Port Lock802.1X Table Using Auto Warning Configuring Email WarningEmail Alarm Events Settings System Event MoxaEtherDeviceSwitch0001@SwitchLocationEvent Types Port EventEmail Settings Configuring Relay Event Types Configuring Relay WarningRelay Alarm Events Settings Activate your settingsRelay Alarm List Override relay alarm settingsConfiguring Line-Swap Fast Recovery Using Line-Swap-Fast-RecoveryUsing Set Device IP Enable Line-Swap-Fast-RecoveryConfiguring Set Device IP Set up the connected devicesOutput data stream Using DiagnosisMirror Port Bi-directionalUsing Monitor Monitor by SwitchPing Using the MAC Address Table Monitor by PortUsing Event Log ALLEDS Configurator GUI Starting EDS Configurator Broadcast SearchUpgrade Firmware Search by IP addressModify IP Address Export Configuration Import Configuration Unlock Server EDS-726 Series User’s Manual MIB II.4 IP Group MIB II.1 System GroupMIB II.2 Interfaces Group MIB II.5 Icmp GroupMIB II.10 Transmission Group MIB II.11 Snmp GroupMIB II.17 dot1dBridge Group Public Traps Private TrapsModular Managed Switch System, EDS-72610G InterfacePower Gigabit Ethernet Interface Module, IM seriesMechanical Fast Ethernet Interface Module, IM series Optical FiberInterface Environmental Regulatory ApprovalsService Information Moxa Internet Services Following services are providedProblem Report Form Serial NumberProduct Return Procedure
Top Page Image Contents