Table Of Contents
Configuring Fibre Channel Routing Services and Protocols
About FSPF
FSPF Examples
Fault Tolerant Fabric
Redundant Links
Fail-Over Scenarios for PortChannels and FSPF Links
FSPF Global Configuration
About SPF Computational Hold Times
About Link State Record Defaults
Configuring FSPF on a VSAN
Resetting FSPF to the Default Configuration
Enabling or Disabling FSPF
Clearing FSPF Counters for the VSAN
FSPF Interface Configuration
About FSPF Link Cost
Configuring FSPF Link Cost
About Hello Time Intervals
Configuring Hello Time Intervals
About Dead Time Intervals
Configuring Dead Time Intervals
About Retransmitting Intervals
Configuring Retransmitting Intervals
About Disabling FSPF for Specific Interfaces
Disabling FSPF for Specific Interfaces
Clearing FSPF Counters for an Interface
FSPF Routes
About Fibre Channel Routes
Configuring Fibre Channel Routes
About Broadcast and Multicast Routing
About Multicast Root Switch
Setting the Multicast Root Switch
In-Order Delivery
About Reordering Network Frames
About Reordering PortChannel Frames
About Enabling In-Order Delivery
Enabling In-Order Delivery Globally
Enabling In-Order Delivery for a VSAN
Displaying the In-Order Delivery Status
Configuring the Drop Latency Time
Displaying Latency Information
Flow Statistics Configuration
About Flow Statistics
Counting Aggregated Flow Statistics
Counting Individual Flow Statistics
Clearing FIB Statistics
Displaying Flow Statistics
Displaying Global FSPF Information
Displaying the FSPF Database
Displaying FSPF Interfaces
Default Settings
Configuring Fibre Channel Routing Services and Protocols
Fabric Shortest Path First (FSPF) is the standard path selection protocol used by Fibre Channel fabrics. The FSPF feature is enabled by default on all Fibre Channel switches. Except in configurations that require special consideration, you do not need to configure any FSPF services. FSPF automatically calculates the best path between any two switches in a fabric. Specifically, FSPF is used to:
•Dynamically compute routes throughout a fabric by establishing the shortest and quickest path between any two switches.
•Select an alternative path in the event of the failure of a given path. FSPF supports multiple paths and automatically computes an alternative path around a failed link. It provides a preferred route when two equal paths are available.
This chapter provides details on Fibre Channel routing services and protocols. It includes the following sections:
•About FSPF
•FSPF Global Configuration
•FSPF Interface Configuration
•FSPF Routes
•In-Order Delivery
•Flow Statistics Configuration
•Default Settings
About FSPF
FSPF is the protocol currently standardized by the T11 committee for routing in Fibre Channel networks. The FSPF protocol has the following characteristics and features:
•Supports multipath routing.
•Bases path status on a link state protocol.
•Routes hop by hop, based only on the domain ID.
•Runs only on E ports or TE ports and provides a loop free topology.
•Runs on a per VSAN basis. Connectivity in a given VSAN in a fabric is guaranteed only for the switches configured in that VSAN.
•Uses a topology database to keep track of the state of the links on all switches in the fabric and associates a cost with each link.
•Guarantees a fast reconvergence time in case of a topology change. Uses the standard Dijkstra's algorithm, but there is a static dynamic option for a more robust, efficient, and incremental Dijkstra's algorithm. The reconvergence time is fast and efficient as the route computation is done on a per VSAN basis.
FSPF Examples
Note The FSPF feature can be used on any topology.
Fault Tolerant Fabric
Figure 26-1 Fault Tolerant Fabric
For example, if all links are of equal speed, the FSPF calculates two equal paths from A to C: A-D-C (green) and A-E-C (blue).
Redundant Links
To further improve on the topology in Figure 26-1, each connection between any pair of switches can be replicated; two or more links can be present between a pair of switches. Figure 26-2 shows this arrangement. Because switches in the Cisco MDS 9000 Family support PortChanneling, each pair of physical links can appear to the FSPF protocol as one single logical link.
By bundling pairs of physical links, FSPF efficiency is considerably improved by the reduced database size and the frequency of link updates. Once physical links are aggregated, failures are not attached to a single link but to the entire PortChannel. This configuration also improves the resiliency of the network. The failure of a link in a PortChannel does not trigger a route change, thereby reducing the risks of routing loops, traffic loss, or fabric downtime for route reconfiguration.
Figure 26-2 Fault Tolerant Fabric with Redundant Links
For example, if all links are of equal speed and no PortChannels exist, the FSPF calculates four equal paths from A to C: A1-E-C, A2-E-C, A3-D-C, and A4-D-C. If PortChannels exist, these paths are reduced to two.
Fail-Over Scenarios for PortChannels and FSPF Links
The SmartBits traffic generator was used to evaluate the scenarios displayed in Figure 26-3. Two links between switch 1 and switch 2 exist as either equal-cost ISLs or PortChannels. There is one flow from traffic generator 1 to traffic generator 2. The traffic was tested at 100% utilization at 1 Gbps in two scenarios:
•Disabling the traffic link by physically removing the cable (see Table 26-1).
•Shutting down either switch 1 or switch 2 (see Table 26-2).
Figure 26-3 Fail-Over Scenario Using Traffic Generators
Table 26-1 Physically Removing the Cable for the SmartBits Scenario
PortChannel Scenario
|
FSPF Scenario (Equal cost ISL)
|
Switch 1
|
Switch 2
|
Switch 1
|
Switch 2
|
110 msec (~2K frame drops)
|
130+ msec (~4k frame drops)
|
100 msec (hold time when a signal loss is reported as mandated by the standard)
|
Table 26-2 Shutting Down the Switch for the SmartBits Scenario
PortChannel Scenario
|
FSPF Scenario (Equal cost ISL)
|
Switch 1
|
Switch 2
|
Switch 1
|
Switch 2
|
~0 msec (~8 frame drops)
|
110 msec (~2K frame drops)
|
130+ msec (~4K frame drops)
|
No hold time needed
|
Signal loss on switch 1
|
No hold time needed
|
Signal loss on switch 1
|
FSPF Global Configuration
By default, FSPF is enabled on switches in the Cisco MDS 9000 Family.
Some FSPF features can be globally configured in each VSAN. By configuring a feature for the entire VSAN, you do not have to specify the VSAN number for every command. This global configuration feature also reduces the chance of typing errors or other minor configuration errors.
Note FSPF is enabled by default. Generally, you do not need to configure these advanced features.
Caution The default for the backbone region is 0 (zero). You do not need to change this setting unless your region is different from the default. If you are operating with other vendors using the backbone region, you can change this default to be compatible with those settings.
This section includes the following topics:
•About SPF Computational Hold Times
•About Link State Record Defaults
•Configuring FSPF on a VSAN
•Resetting FSPF to the Default Configuration
•Enabling or Disabling FSPF
•Clearing FSPF Counters for the VSAN
About SPF Computational Hold Times
The SPF computational hold time sets the minimum time between two consecutive SPF computations on the VSAN. Setting this to a small value means that FSPF reacts faster to any fabric changes by recomputing paths on the VSAN. A small SPF computational hold time uses more switch CPU time.
About Link State Record Defaults
Each time a new switch enters the fabric, a link state record (LSR) is sent to the neighboring switches, and then flooded throughout the fabric. Table 26-3 displays the default settings for switch responses.
Table 26-3 LSR Default Settings
LSR Option
|
Default
|
Description
|
Acknowledgment interval (RxmtInterval)
|
5 seconds
|
The time a switch waits for an acknowledgment from the LSR before retransmission.
|
Refresh time (LSRefreshTime)
|
30 minutes
|
The time a switch waits before sending an LSR refresh transmission.
|
Maximum age (MaxAge)
|
60 minutes
|
The time a switch waits before dropping the LSR from the database.
|
The LSR minimum arrival time is the period between receiving LSR updates on this VSAN. Any LSR updates that arrive before the LSR minimum arrival time are discarded.
The LSR minimum interval time is the frequency at which this switch sends LSR updates on a VSAN.
Configuring FSPF on a VSAN
To configure an FSPF feature for the entire VSAN, follow these steps:
|
Command
|
Purpose
|
Step 1
|
switch# config t
switch(config)#
|
Enters configuration mode.
|
Step 2
|
switch(config)# fspf config vsan 1
|
Enters FSPF global configuration mode for the specified VSAN.
|
Step 3
|
switch-config-(fspf-config)# spf static
|
Forces static SPF computation for the dynamic (default) incremental VSAN.
|
Step 4
|
switch-config-(fspf-config)# spf hold-time 10
|
Configures the hold time between two route computations in milliseconds (msec) for the entire VSAN. The default value is 0.
Note If the specified time is shorter, the routing is faster. However, the processor consumption increases accordingly.
|
Step 5
|
switch-config-(fspf-config)# region 7
|
Configures the autonomous region for this VSAN and specifies the region ID (7).
|
Resetting FSPF to the Default Configuration
To return the FSPF VSAN global configuration to its factory default, follow these steps:
|
Command
|
Purpose
|
Step 1
|
switch# config t
switch(config)#
|
Enters configuration mode.
|
Step 2
|
switch(config)# no fspf config vsan 3
|
Deletes the FSPF configuration for VSAN 3.
|
Enabling or Disabling FSPF
To enable or disable FSPF routing protocols, follow these steps:
|
Command
|
Purpose
|
Step 1
|
switch# config t
switch(config)#
|
Enters configuration mode.
|
Step 2
|
switch(config)# fspf enable vsan 7
|
Enables the FSPF routing protocol in VSAN 7.
|
switch(config)# no fspf enable vsan 5
|
Disables the FSPF routing protocol in VSAN 5.
|
Clearing FSPF Counters for the VSAN
To clear the FSPF statistics counters for the entire VSAN, follow this step:
|
Command
|
Purpose
|
Step 1
|
switch# clear fspf counters vsan 1
|
Clears the FSPF statistics counters for the specified VSAN. If an interface reference is not specified, all counters are cleared.
|
FSPF Interface Configuration
Several FSPF commands are available on a per interface basis. These configuration procedures apply to an interface in a specific VSAN.
This section includes the following topics:
•About FSPF Link Cost
•Configuring FSPF Link Cost
•About Hello Time Intervals
•Configuring Hello Time Intervals
•About Dead Time Intervals
•Configuring Dead Time Intervals
•About Retransmitting Intervals
•Configuring Retransmitting Intervals
•About Disabling FSPF for Specific Interfaces
•Disabling FSPF for Specific Interfaces
•Clearing FSPF Counters for an Interface
About FSPF Link Cost
FSPF tracks the state of links on all switches in the fabric, associates a cost with each link in its database, and then chooses the path with a minimal cost. The cost associated with an interface can be administratively changed to implement the FSPF route selection. The integer value to specify cost can range from 1 to 65,535. The default cost for 1 Gbps is 1000 and for 2 Gbps is 500.
Configuring FSPF Link Cost
To configure FSPF link cost, follow these steps:
|
Command
|
Purpose
|
Step 1
|
switch# config t
switch(config)#
|
Enters configuration mode.
|
Step 2
|
switch(config)# interface fc1/4
switch(config-if)#
|
Configures the specified interface, or if already configured, enters configuration mode for the specified interface.
|
Step 3
|
switch(config-if)# fspf cost 5 vsan 90
|
Configures the cost for the selected interface in VSAN 90.
|
About Hello Time Intervals
You can set the FSPF Hello time interval to specify the interval between the periodic hello messages sent to verify the health of the link. The integer value can range from 1 to 65,535 seconds.
Note This value must be the same in the ports at both ends of the ISL.
Configuring Hello Time Intervals
To configure the FSPF Hello time interval, follow these steps:
|
Command
|
Purpose
|
Step 1
|
switch# config t
switch(config)#
|
Enters configuration mode.
|
Step 2
|
switch(config)# interface fc1/4
switch(config-if)#
|
Configures the specified interface, or if already configured, enters configuration mode for the specified interface.
|
Step 3
|
switch(config-if)# fspf hello-interval 15 vsan 175
switch(config-if)#
|
Specifies the hello message interval (15 seconds) to verify the health of the link in VSAN 175. The default is 20 seconds.
|
About Dead Time Intervals
You can set the FSPF dead time interval to specify the maximum interval for which a hello message must be received before the neighbor is considered lost and removed from the database. The integer value can range from 1 to 65,535 seconds.
Note This value must be the same in the ports at both ends of the ISL.
Caution An error is reported at the command prompt if the configured dead time interval is less than the hello time interval.
Configuring Dead Time Intervals
To configure the FSPF dead time interval, follow these steps:
|
Command
|
Purpose
|
Step 1
|
switch# config t
switch(config)#
|
Enters configuration mode.
|
Step 2
|
switch(config)# interface fc1/4
switch(config-if)#
|
Configures the specified interface, or if already configured, enters configuration mode for the specified interface.
|
Step 3
|
switch(config-if)# fspf dead-interval 25
vsan 7
switch(config-if)#
|
Specifies the maximum interval for VSAN 7 before which a hello message must be received on the selected interface before the neighbor is considered lost. The default is 80 seconds.
|
About Retransmitting Intervals
You can specify the time after which an unacknowledged link state update should be transmitted on the interface. The integer value to specify retransmit intervals can range from 1 to 65,535 seconds.
Note This value must be the same on the switches on both ends of the interface.
Configuring Retransmitting Intervals
To configure the FSPF retransmit time interval, follow these steps:
|
Command
|
Purpose
|
Step 1
|
switch# config t
switch(config)#
|
Enters configuration mode.
|
Step 2
|
switch(config)# interface fc1/4
switch(config-if)#
|
Configures the specified interface, or if already configured, enters configuration mode for the specified interface.
|
Step 3
|
switch(config-if)# fspf retransmit-interval
15 vsan 12
switch(config-if)#
|
Specifies the retransmit time interval for unacknowledged link state updates in VSAN 12. The default is 5 seconds.
|
About Disabling FSPF for Specific Interfaces
You can disable the FSPF protocol for selected interfaces. By default, FSPF is enabled on all E ports and TE ports. This default can be disabled by setting the interface as passive.
Note FSPF must be enabled at both ends of the interface for the protocol to work.
Disabling FSPF for Specific Interfaces
You can disable the FSPF protocol for selected interfaces. By default, FSPF is enabled on all E ports and TE ports. This default can be disabled by setting the interface as passive.
To disable FSPF for a specific interface, follow these steps:
|
Command
|
Purpose
|
Step 1
|
switch# config t
switch(config)#
|
Enters configuration mode.
|
Step 2
|
switch(config)# interface fc1/4
switch(config-if)#
|
Configures a specified interface, or if already configured, enters configuration mode for the specified interface.
|
Step 3
|
switch(config-if)# fspf passive vsan 1
switch(config-if)#
|
Disables the FSPF protocol for the specified interface in the specified VSAN.
|
switch(config-if)# no fspf passive vsan 1
switch(config-if)#
|
Reenables the FSPF protocol for the specified interface in the specified VSAN.
|
You can disable the FSPF protocol for selected interfaces. By default, FSPF is enabled on all E ports and TE ports. This default can be disabled by setting the interface as passive.
Clearing FSPF Counters for an Interface
To clear the FSPF statistics counters for an interface, follow this step:
|
Command
|
Purpose
|
Step 4
|
switch# clear fspf counters vsan 200 interface fc1/1
|
Clears the FSPF statistics counters for the specified interface in VSAN 200.
|
FSPF Routes
FSPF routes traffic across the fabric, based on entries in the FSPF database. These routes can be learned dynamically, or configured statically.
This section includes the following topics:
•About Fibre Channel Routes
•Configuring Fibre Channel Routes
•About Broadcast and Multicast Routing
•About Multicast Root Switch
•Setting the Multicast Root Switch
About Fibre Channel Routes
Each port implements forwarding logic, which forwards frames based on its FC ID. Using the FC ID for the specified interface and domain, you can configure the specified route (for example FC ID 111211 and domain ID 3) in the switch with domain ID 1 (see Figure 26-4).
Figure 26-4 Fibre Channel Routes
Note Other than in VSANs, runtime checks are not performed on configured and suspended static routes.
Configuring Fibre Channel Routes
To configure a Fibre Channel route, follow these steps:
|
Command
|
Purpose
|
Step 1
|
switch# config t
switch(config)#
|
Enters configuration mode.
|
Step 2
|
switch(config)# fcroute 0x111211
interface fc1/1 domain 3 vsan 2
switch(config)#
|
Configures the route for the specified Fibre Channel interface and domain. In this example, interface fc1/1 is assigned an FC ID (0x111211) and a domain ID (3) to the next hop switch.
|
switch(config)# fcroute 0x111211
interface port-channel 1 domain 3 vsan 4
switch(config)#
|
Configures the route for the specified PortChannel interface and domain. In this example, interface port-channel 1 is assigned an FC ID (0x111211) and a domain ID (3) to the next hop switch.
|
switch(config)# fcroute 0x031211
interface fc1/1 domain 3 metric 1 vsan 1
switch(config-if)#
|
Configures the static route for a specific FC ID and next hop domain ID and also assigns the cost of the route.
If the remote destination option is not specified, the default is direct.
|
switch(config)# fcroute 0x111112
interface fc1/1 domain 3 metric 3 remote
vsan 3
|
Adds a static route to the RIB. If this is an active route and the FIB1 records are free, it is also added to the FIB.
If the cost (metric) of the route is not specified, the default is 10.
|
Step 3
|
switch(config)# fcroute 0x610000
0xff0000 interface fc 1/1 domain 1 vsan
2
switch(config)#
|
Configures the netmask for the specified route in interface fc1/1 (or PortChannel). You can specify one of three routes: 0xff0000 matches only the domain, 0xffff00 matches the domain and the area, 0xffffff matches the domain, area, and port.
|
About Broadcast and Multicast Routing
Broadcast and multicast in a Fibre Channel fabric uses the concept of a distribution tree to reach all switches in the fabric.
FSPF provides the topology information to compute the distribution tree. Fibre Channel defines 256 multicast groups and one broadcast address for each VSAN. Switches in the Cisco MDS 9000 Family only use broadcast routing. By default, they use the principal switch as the root node to derive a loop-free distribution tree for multicast and broadcast routing in a VSAN.
Caution All switches in the fabric should run the same multicast and broadcast distribution tree algorithm to ensure the same distribution tree.
To interoperate with other vendor switches (following FC-SW3 guidelines), the SAN-OS software uses the lowest domain switch as the root to compute the multicast tree in interop mode.
About Multicast Root Switch
By default, the native (non-interop) mode uses the principal switch as the root. If you change the default, be sure to configure the same mode in all switches in the fabric. Otherwise, multicast traffic could face potential loop and frame-drop problems.
Note The operational mode can be different from the configured interop mode. The interop mode always uses the lowest domain switch as the root.
Use the mcast root lowest vsan command to change the multicast root from the principal switch to lowest domain switch.
Setting the Multicast Root Switch
To use the lowest domain switch for the multicast tree computation, follow these steps:
|
Command
|
Purpose
|
Step 1
|
switch# config t
switch(config)#
|
Enters configuration mode.
|
Step 2
|
switch(config)# mcast root lowest vsan 1
|
Uses the lowest domain switch to compute the multicast tree.
|
switch(config)# mcast root principal vsan 1
|
Defaults to using the principal switch to compute the multicast tree.
|
To display the configured and operational multicast mode and the selected root domain, use the show mcast command.
switch# show mcast vsan 1
Multicast root for VSAN 1
Configured root mode : Principal switch
Operational root mode : Principal switch
Root Domain ID : 0xef(239)
In-Order Delivery
In-Order Delivery (IOD) of data frames guarantees frame delivery to a destination in the same order that they were sent by the originator.
Some Fibre Channel protocols or applications cannot handle out-of-order frame delivery. In these cases, switches in the Cisco MDS 9000 Family preserve frame ordering in the frame flow. The source ID (SID), destination ID (DID), and optionally the originator exchange ID (OX ID) identify the flow of the frame.
On any given switch with IOD enabled, all frames received by a specific ingress port and destined to a certain egress port are always delivered in the same order in which they were received.
Use IOD only if your environment cannot support out-of-order frame delivery.
Tip If you enable the in-order delivery feature, the graceful shutdown feature is not implemented.
This section includes the following topics:
•About Reordering Network Frames
•About Reordering PortChannel Frames
•About Enabling In-Order Delivery
•Enabling In-Order Delivery Globally
•Enabling In-Order Delivery for a VSAN
•Displaying the In-Order Delivery Status
•Configuring the Drop Latency Time
•Displaying Latency Information
About Reordering Network Frames
When you experience a route change in the network, the new selected path may be faster or less congested than the old route.
Figure 26-5 Route Change Delivery
In Figure 26-5, the new path from Switch 1 to Switch 4 is faster. In this scenario, Frame 3 and Frame 4 may be delivered before Frame 1 and Frame 2.
If the in-order guarantee feature is enabled, the frames within the network are treated as follows:
•Frames in the network are delivered in the order in which they are transmitted.
•Frames that cannot be delivered in order within the network latency drop period are dropped inside the network.
About Reordering PortChannel Frames
When a link change occurs in a PortChannel, the frames for the same exchange or the same flow can switch from one path to another faster path.
Figure 26-6 Link Congestion Delivery
In Figure 26-6, the port of the old path (red dot) is congested. In this scenario, Frame 3 and Frame 4 can be delivered before Frame 1 and Frame 2.
The the in-order delivery feature attempts to minimize the number of frames dropped during PortChannel link changes when the in-order delivery is enabled by sending a request to the remote switch on the PortChannel to flush all frames for this PortChannel.
Note Both switches on the PortChannel must be running Cisco SAN-OS Release 3.0(1) for this IOD enhancement. For earlier releases, IOD waits for the switch latency period before sending new frames.
When the in-order delivery guarantee feature is enabled and a PortChannel link change occurs, the frames crossing the PortChannel are treated as follows:
•Frames using the old path are delivered before new frames are accepted.
•The new frames are delivered through the new path after the switch latency drop period has elapsed and all old frames are flushed.
Frames that cannot be delivered in order through the old path within the switch latency drop period are dropped. See the "Configuring the Drop Latency Time" section.
About Enabling In-Order Delivery
You can enable the in-order delivery feature for a specific VSAN or for the entire switch. By default, in-order delivery is disabled on switches in the Cisco MDS 9000 Family.
Tip We recommend that you only enable this feature when devices that cannot handle any out-of-order frames are present in the switch. Load-balancing algorithms within the Cisco MDS 9000 Family ensure that frames are delivered in order during normal fabric operation. The load-balancing algorithms based on source FC ID, destination FC ID, and exchange ID are enforced in hardware without any performance degradation. However, if the fabric encounters a failure and this feature is enabled, the recovery will be delayed because of an intentional pausing of fabric forwarding to purge the fabric of resident frames that could potentially be forwarded out-of-order.
Enabling In-Order Delivery Globally
To ensure that the in-order delivery parameters are uniform across all VSANs on an MDS switch, enable in-order delivery globally.
Only enable in-order delivery globally if this is a requirement across your entire fabric. Otherwise, enable IOD only for the VSANs that require this feature.
Note Enable in-order delivery on the entire switch before performing a downgrade to Cisco MDS SAN-OS Release1.3(3) or earlier.
To enable in-order delivery for the switch, follow these steps:
|
Command
|
Purpose
|
Step 1
|
switch# config t
switch(config)#
|
Enters configuration mode.
|
Step 2
|
switch(config)# in-order-guarantee
|
Enables in-order delivery in the switch.
|
switch(config)# no in-order-guarantee
|
Reverts the switch to the factory defaults and disables the in-order delivery feature.
|
Enabling In-Order Delivery for a VSAN
When you create a VSAN, that VSAN automatically inherits the global in-order-guarantee value. You can override this global value by enabling or disabling in-order-guarantee for the new VSAN.
To use the lowest domain switch for the multicast tree computation, follow these steps:
|
Command
|
Purpose
|
Step 1
|
switch# config t
switch(config)#
|
Enters configuration mode.
|
Step 2
|
switch(config)# in-order-guarantee vsan 3452
|
Enables in-order delivery in VSAN 3452.
|
switch(config)# no in-order-guarantee vsan 101
|
Reverts the switch to the factory defaults and disables the in-order delivery feature in VSAN 101.
|
Displaying the In-Order Delivery Status
Use the show in-order-guarantee command to display the present configuration status:
switch# show in-order-guarantee
global inorder delivery configuration:guaranteed
vsan 1 inorder delivery:guaranteed
vsan 101 inorder delivery:not guaranteed
vsan 1000 inorder delivery:guaranteed
vsan 1001 inorder delivery:guaranteed
vsan 1682 inorder delivery:guaranteed
vsan 2001 inorder delivery:guaranteed
vsan 2009 inorder delivery:guaranteed
vsan 2456 inorder delivery:guaranteed
vsan 3277 inorder delivery:guaranteed
vsan 3451 inorder delivery:guaranteed
vsan 3452 inorder delivery:guaranteed
Configuring the Drop Latency Time
You can change the default latency time for a network, a specified VSAN in a network, or for the entire switch.
To configure the network and the switch drop latency time, follow these steps:
|
Command
|
Purpose
|
Step 1
|
switch# config t
switch(config)#
|
Enters configuration mode.
|
Step 2
|
switch(config)# fcdroplatency network 5000
|
Configures network drop latency time to be 5000 msec for the network. The valid range is 0 to 60000 msec. The default is 2000 msec.
Note The network drop latency must be computed as the sum of all switch latencies of the longest path in the network
|
switch(config)# fcdroplatency network 6000
vsan 3
|
Configures network drop latency time to be 6000 msec for VSAN 3.
|
switch(config)# no fcdroplatency network
4500
|
Removes the current fcdroplatecy network configuration (4500) and reverts the switch to the factory defaults.
|
Step 3
|
switch(config)# fcdroplatency switch 4000
|
Configures switch drop latency time to be 4000 msec for the switch. The valid range is 0 to 60000 msec. The default is 500 msec.
Note The switch drop latency parameter should have the same value in all the switches in the network
|
switch(config)# no fcdroplatency switch
4500
|
Removes the current fcdroplatecy switch configuration (4500) and reverts the switch to the factory defaults.
|
Displaying Latency Information
You can view the configured latency parameters using the show fcdroplatency command (see Example 26-1).
Example 26-1 Displays Administrative Distance
switch# show fcdroplatency
switch latency value:500 milliseconds
global network latency value:2000 milliseconds
VSAN specific network latency settings
vsan 1 network latency:5000 milliseconds
vsan 2 network latency:2000 milliseconds
vsan 103 network latency:2000 milliseconds
vsan 460 network latency:500 milliseconds
Flow Statistics Configuration
Flow statistics count the ingress traffic in the aggregated statistics table. You can collect two kinds of statistics:
•Aggregated flow statistics to count the traffic for a VSAN.
•Flow statistics to count the traffic for a source and destination ID pair in a VSAN.
This section includes the following topics:
•About Flow Statistics
•Counting Aggregated Flow Statistics
•Counting Individual Flow Statistics
•Clearing FIB Statistics
•Displaying Global FSPF Information
About Flow Statistics
If you enable flow counters, you can enable a maximum of 1K entries for aggregate flow and flow statistics for Generation 1 modules, and 2 K entries for Generation 2 modules. Be sure to assign an unused flow index to a module for each new flow. Flow indexes can be repeated across modules. The number space for flow index is shared between the aggregate flow statistics and the flow statistics.
Generation 1 modules allow a maximum of 1024 flow statements per module. Generation 2 modules allow a maximum of 2048-128 flow statements per module.
Counting Aggregated Flow Statistics
To count the aggregated flow statistics for a VSAN, follow these steps:
|
Command
|
Purpose
|
Step 1
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switch# config t
switch(config)#
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Enters configuration mode.
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Step 2
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switch(config)# fcflow stats aggregated module 1
index 1005 vsan 1
switch(config)#
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Enables the aggregated flow counter.
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switch(config)# no fcflow stats aggregated module
1 index 1005 vsan 1
switch(config)#
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Disables the aggregated flow counter.
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Counting Individual Flow Statistics
To count the flow statistics for a source and destination FC ID in a VSAN, follow these steps:
|
Command
|
Purpose
|
Step 1
|
switch# config t
switch(config)#
|
Enters configuration mode.
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Step 2
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switch(config)# fcflow stats module 1 index 1
0x145601 0x5601ff 0xffffff vsan 1
switch(config)#
|
Enables the flow counter.
Note The source ID and the destination ID are specified in FC ID hex format (for example, 0x123aff). The mask can be one of 0xff0000 or 0xffffff.
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switch(config)# no fcflow stats aggregated module
2 index 1001 vsan 2
switch(config)#
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Disables the flow counter.
|
Clearing FIB Statistics
Use the clear fcflow stats command to clear the aggregated flow counter (see Examples 26-2 and 26-3).
Example 26-2 Clears Aggregated Flow Counters
switch# clear fcflow stats aggregated module 2 index 1
Example 26-3 Clears Flow Counters for Source and Destination FC IDs
switch# clear fcflow stats module 2 index 1
Displaying Flow Statistics
Use the show fcflow stats commands to view flow statistics (see Example 26-4 to 26-6).
Example 26-4 Displays Aggregated Flow Details for the Specified Module
switch# show fcflow stats aggregated module 2
Idx VSAN # frames # bytes
---- ---- -------- -------
0000 4 387,653 674,235,875
Example 26-5 Displays Flow Details for the Specified Module
switch# show fcflow stats module 2
Idx VSAN D ID S ID mask # frames # bytes
---- ---- ----------- ----------- ----- -------- -------
0000 4 032.001.002 007.081.012 ff.ff.ff 387,653 674,235,875
0001 6 004.002.001 019.002.004 ff.00.00 34,402 2,896,628
Example 26-6 Displays Flow Index Usage for the Specified Module
switch# show fcflow stats usage module 2
Displaying Global FSPF Information
Example 26-7 displays global FSPF information for a specific VSAN:
•Domain number of the switch.
•Autonomous region for the switch.
•Min_LS_arrival: minimum time that must elapse before the switch accepts LSR updates.
•Min_LS_interval: minimum time that must elapse before the switch can transmit an LSR.
Tip If the Min_LS_interval is higher than 10 seconds, the graceful shutdown feature is not implemented.
•LS_refresh_time: interval time lapse between refresh LSR transmissions.
•Max_age: maximum time aa LSR can stay before being deleted.
Example 26-7 Displays FSPF Information for a Specified VSAN
FSPF routing administration status is enabled
FSPF routing operational status is UP
It is an intra-domain router
MinLsArrival = 1000 msec , MinLsInterval = 5000 msec
Local Domain is 0x65(101)
Number of LSRs = 3, Total Checksum = 0x0001288b
LS_REFRESH_TIME = 1800 sec
Number of LSR that reached MaxAge = 0
Number of SPF computations = 7
Number of Checksum Errors = 0
Number of Transmitted packets : LSU 65 LSA 55 Hello 474 Retranmsitted LSU 0
Number of received packets : LSU 55 LSA 60 Hello 464 Error packets 10
Displaying the FSPF Database
Example 26-8 displays a summary of the FSPF database for a specified VSAN. If other parameters are not specified, all LSRs in the database are displayed:
•LSR type
•Domain ID of the LSR owner
•Domain ID of the advertising router
•LSR age
•LSR incarnation member
•Number of links
You could narrow the display to obtain specific information by issuing additional parameters for the domain ID of the LSR owner. For each interface, the following information is also available:
•Domain ID of the neighboring switch
•E port index
•Port index of the neighboring switch
•Link type and cost
Example 26-8 Displays FSPF Database Information
switch# show fspf database vsan 1
FSPF Link State Database for VSAN 1 Domain 0x0c(12)
Advertising domain ID = 0x0c(12)
LSR Incarnation number = 0x80000024
NbrDomainId IfIndex NbrIfIndex Link Type Cost
-----------------------------------------------------------------------------
0x65(101) 0x0000100e 0x00001081 1 500
0x65(101) 0x0000100f 0x00001080 1 500
FSPF Link State Database for VSAN 1 Domain 0x65(101)
Advertising domain ID = 0x65(101)
LSR Incarnation number = 0x80000028
NbrDomainId IfIndex NbrIfIndex Link Type Cost
-----------------------------------------------------------------------------
0xc3(195) 0x00001085 0x00001095 1 500
0xc3(195) 0x00001086 0x00001096 1 500
0xc3(195) 0x00001087 0x00001097 1 500
0xc3(195) 0x00001084 0x00001094 1 500
0x0c(12) 0x00001081 0x0000100e 1 500
0x0c(12) 0x00001080 0x0000100f 1 500
FSPF Link State Database for VSAN 1 Domain 0xc3(195)
Advertising domain ID = 0xc3(195)
LSR Incarnation number = 0x80000033
NbrDomainId IfIndex NbrIfIndex Link Type Cost
-----------------------------------------------------------------------------
0x65(101) 0x00001095 0x00001085 1 500
0x65(101) 0x00001096 0x00001086 1 500
0x65(101) 0x00001097 0x00001087 1 500
0x65(101) 0x00001094 0x00001084 1 500
Displaying FSPF Interfaces
Example 26-9 displays the following information for each selected interface.
•Link cost
•Timer values
•Neighbor's domain ID (if known)
•Local interface number
•Remote interface number (if known)
•FSPF state of the interface
•Interface counters
Example 26-9 Displays FSPF Interface Information
switch# show fspf vsan 1 interface fc1/1
FSPF interface fc1/1 in VSAN 1
FSPF routing administrative state is active
Timer intervals configured, Hello 20 s, Dead 80 s, Retransmit 5 s
Neighbor Domain Id is 0x0c(12), Neighbor Interface index is 0x0f100000
Number of packets received : LSU 8 LSA 8 Hello 118 Error packets 0
Number of packets transmitted : LSU 8 LSA 8 Hello 119 Retransmitted LSU 0
Number of times inactivity timer expired for the interface = 0
Default Settings
Table 26-4 lists the default settings for FSPF features.
Table 26-4 Default FSPF Settings
Parameters
|
Default
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FSPF
|
Enabled on all E ports and TE ports.
|
SPF computation
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Dynamic.
|
SPF hold time
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0.
|
Backbone region
|
0.
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Acknowledgment interval (RxmtInterval)
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5 seconds.
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Refresh time (LSRefreshTime)
|
30 minutes.
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Maximum age (MaxAge)
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60 minutes.
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Hello interval
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20 seconds.
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Dead interval
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80 seconds.
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Distribution tree information
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Derived from the principal switch (root node).
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Routing table
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FSPF stores up to 16 equal cost paths to a given destination.
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Load balancing
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Based on destination ID and source ID on different, equal cost paths.
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In-order delivery
|
Disabled.
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Drop latency
|
Disabled.
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Static route cost
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If the cost (metric) of the route is not specified, the default is 10.
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Remote destination switch
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If the remote destination switch is not specified, the default is direct.
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Multicast routing
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Uses the principal switch to compute the multicast tree.
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