Moxa Technologies EDS-726 Configuration Limits of RSTP/STP, Enable STP per Port, Port Priority

Page 46

 

EDS-726 Series User’s Manual

Featured Functions

 

 

Enable STP per Port

 

 

 

 

 

 

 

 

 

 

 

Setting

Description

Factory Default

 

 

 

Enable/Disable

Select to enable the port as a node on the

Disabled

 

 

 

 

Spanning Tree topology.

 

 

 

 

 

 

NOTE

We suggest not enabling the Spanning Tree Protocol once the port is connected to a device (PLC,

 

 

RTU, etc.) as opposed to network equipment. The reason is that it will cause unnecessary

 

 

negotiation.

 

 

 

 

 

 

 

 

 

 

 

Port Priority

 

 

 

 

 

Setting

Description

Factory Default

 

 

 

Numerical value selected

Increase this port’s priority as a node on the

128

 

 

 

by user

Spanning Tree topology by inputting a lower

 

 

 

 

 

number.

 

 

 

 

Port Cost

 

 

 

 

 

Setting

Description

Factory Default

 

 

 

Numerical value input by

Input a higher cost to indicate that this port is

200000

 

 

 

user

less suitable as a node for the Spanning Tree

 

 

 

 

 

topology.

 

 

Port Status

Indicates the current Spanning Tree status of this port. “Forwarding” for normal transmission, or “Blocking” to block transmission.

Configuration Limits of RSTP/STP

The Spanning Tree Algorithm places limits on three of the configuration items described above:

[Eq. 1]:

1 sec

Hello Time 10 sec

[Eq. 2]:

6 sec Max. Age 40 sec

[Eq. 3]:

4 sec

Forwarding Delay 30 sec

These three variables are further restricted by the following two inequalities:

[Eq. 4]: 2 * (Hello Time + 1 sec) Max. Age 2 * (Forwarding Delay – 1 sec)

MOXA EDS-726’s firmware will alert you immediately if any of these restrictions are violated. For example, setting

Hello Time = 5 sec, Max. Age = 20 sec, and Forwarding Delay = 4 sec does not violate Eqs. 1 through 3, but does violate Eq. 4, since in this case,

2 * (Hello Time + 1 sec) = 12 sec, and 2 * (Forwarding Delay – 1 sec) = 6 sec.

You can remedy the situation in any number of ways. One solution is simply to increase the Forwarding Delay value to at least 11 sec.

HINT: Take the following steps to avoid guessing:

Step 1: Assign a value to “Hello Time” and then calculate the left most part of Eq. 4 to get the lower limit of “Max. Age.”

Step 2: Assign a value to “Forwarding Delay” and then calculate the right most part of Eq. 4 to get the upper limit for “Max. Age.”

Step 3: Assign a value to “Forwarding Delay” that satisfies the conditions in Eq. 3 and Eq. 4.

3-31

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Contents Moxa EtherDevice Switch EDS-726 Series User’s Manual First Edition, JulyTrademarks Copyright NoticeDisclaimer 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 System File Update-By CF Card Using Port TrunkingFactory 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? STP Requirements How STP WorksPort 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 WorksIeee 802.1p Priority Level Ieee 802.1D Traffic Type Differentiated Services DiffServ Traffic MarkingTraffic Prioritization QoS Classification Configuring Traffic PrioritizationTraffic Queues Inspect TOS Default Port PriorityQueuing Mechanism Inspect COSCoS Mapping Setting Description FactoryTOS/DiffServ Mapping What is a VLAN? Using Virtual LANVirtual 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 KeyLocal User Database Setup 802.1X Re-Authentication802.1X Re-Authentication Static Port Lock Local User Database Setup802.1X Table Configuring Email Warning Using Auto 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-directionalMonitor by Switch Using MonitorPing 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.11 Snmp Group MIB II.10 Transmission GroupMIB II.17 dot1dBridge Group Public Traps Private TrapsModular Managed Switch System, EDS-72610G InterfaceGigabit Ethernet Interface Module, IM series PowerMechanical 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