Dieses Guide wurde erstellt von Daniel Kaps Dell Enterprise Engineer Storage/Network.

 


Introduction

Automatic iSCSI Optimization

via CLI

Via GUI (Webinterface) 

Jumbo Frames

via CLI

Via GUI (Webinterface) 

Spanning Tree PortFast

via CLI

via GUI (Webinterface) 

Flow Control

via CLI

via GUI (Webinterface) 

Storm Control 

via CLI

via GUI (Webinterface) 

 


The PowerConnect 55xx series switches feature automatic iSCSI optimization on interfaces connected to Dell EqualLogic controllers (using automatic discovery through LLDP), while interfaces connected to hosts and additional SAN arrays can be manually configured. This example configuration follows best practices as provided for Dell EqualLogic arrays.

 


Automatic iSCSI Optimization for Dell EqualLogic-connected interfaces

The following steps will enable automatic iSCSI optimization on interfaces attached to Dell EqualLogic controllers. This will also enable jumbo frame support across all interfaces on the 55xx series - note that jumbo frame support will be available after the configuration has been saved and the switch has been reset to adjust for the new frame size.

 

CLI:

 

1. Login to the CLI and enable iSCSI optimization globally:

console>enable

console#configure

console(config)#iscsi enable

 

Switch output:

Enabling iSCSI also automatically enables jumbo-frames. However, jumbo-frames will be enabled only after copying running configuration to startup configuration and resetting the device

 

2. Verify that jumbo frames will be enabled after reset:

console(config)#exit

console#show ports jumbo-frame

 

Jumbo frames are disabled

Jumbo frames will be enabled after reset

 

3. Save the configuration:

console#copy running-config startup-config

Overwrite file [startup-config] ?[Yes/press any key for no]....

%COPY-I-FILECPY: Files Copy - source URL running-config destination URL flash://startup-config

%COPY-N-TRAP: The copy operation was completed successfully

Copy succeeded

 

4. Reset the switch: 

console#reload

This command will reset the whole system and disconnect your current session. Do you want to continue ? (Y/N) Y

Shutting down...


 

Web UI:

1. Navigate to Switching > iSCSI Optimization > Global Parameters. Set "iSCSI Status" to "Enable", then click Apply.

 

2. Click OK to acknowledge that jumbo frames support will require a switch reset:

 

3. Verify that the configuration was successfully applied:

 

4. To save the switch configuration, navigate to System > File Management > Copy Files. Verify that "Copy Configuration" is selected with source "Running Configuration" and destination "Startup Configuration", then click Activate.

 

5. Once the configuration has been copied, click Close:

 

6. To reset the switch to activate jumbo frame support, navigate to System > Stack Management > Reset. Select "Reset Device", then click Apply. Note that this will drop all traffic for several minutes while the switch management is restarted.

 

7. Click OK to confirm the reset

 


 

Jumbo Frames

Jumbo frame support is disabled by default and is configured globally for all interfaces - enabling jumbo frame support is effective after a switch reset:

 


CLI:

 

1. Login to the CLI and enable jumbo frame support globally:

console>enable

console#configure

console(config)#port jumbo-frame

 

This setting will take effect only after copying running configuration to startup configuration and resetting the device

 

2. Verify that jumbo frames will be enabled after reset:

console(config)#exit

console#show ports jumbo-frame

 

Jumbo frames are disabled

Jumbo frames will be enabled after reset

 

3. Save the configuration:

console#copy running-config startup-config

 

Overwrite file [startup-config] ?[Yes/press any key for no]....

%COPY-I-FILECPY: Files Copy - source URL running-config destination URL flash://startup-config

%COPY-N-TRAP: The copy operation was completed successfully

Copy succeeded

 

4. Reset the switch:

console#reload

 

This command will reset the whole system and disconnect your current session. Do you want to continue ? (Y/N)

Shutting down ...

 

5. After the switch has reset, verify that jumbo frames are now enabled:

console>enable

console#show ports jumbo-frame

 

Jumbo frames are enabled

Jumbo frames will be enabled after reset

Web UI:

1. Navigate to Switching > Ports > Jumbo Frames. Set "New Setting" to "Enabled", then click Apply:

 

2. Verify that the configuration was successfully applied:

 

3. Save the configuration via System > File Management > Copy Files - this process is described above in "Automatic iSCSI Optimization". After reset, verify that jumbo frames support is now enabled:

 


Spanning Tree PortFast

The PowerConnect 55xx series switches run IEEE 802.1w Rapid Spanning Tree Protocol by default. For interfaces connected directly to SAN and host NICs, enabling spanning tree portfast ensures that the switch interfaces begins passing traffic immediately when a link is detected, and prevents unnecessary spanning tree topology changes if the interface link state changes (for example, if a host is rebooted). Spanning tree portfast is disabled by default, and is referred as "Fast Link" via the web UI.

 

Note that spanning tree portfast typically should not be enabled on interfaces attached to other network devices (switches, routers, firewalls, etc) to ensure that any network loops are detected prior to passing traffic through the interface.

 


CLI:

 

1. Login to the CLI and enable spanning tree port-fast on the appropriate interfaces - this example configures gigabit interfaces 1-12:

console>enable

console#configure

console(config)#interface range gigabitethernet 1/0/1-12

console(config-if-range)#spanning-tree portfast

 

2. Verify that spanning tree port-fast is enabled on the interface:

console(config-if-range)#end

console#show spanning-tree

 

Spanning tree enabled mode RSTP

...

...

Interfaces

Name State Prio.Nbr Cost Sts Role PortFast Type

--------- -------- -------- -------- ------ ---- -------- -----------------

gi1/0/1 enabled 128.1 2000000 Dsbl Dsbl Yes -

gi1/0/2 enabled 128.2 2000000 Dsbl Dsbl Yes -

...

...

 

3. Save the configuration:

console#copy running-config startup-config

 

 

Overwrite file [startup-config] ?[Yes/press any key for no]....

%COPY-I-FILECPY: Files Copy - source URL running-config destination URL flash://startup-config

%COPY-N-TRAP: The copy operation was completed successfully

Copy succeeded


 

Web UI:

1. After logging into the web UI, navigate to Switching > Spanning Tree -> STP Port Settings > Edit. Select an interface to configure, select "Fast Link", then click Apply:

 

2. After configuring each appropriate interface, select "Summary" to verify that "Fast Link" is enabled:

 

3. Save the configuration via System > File Management > Copy Files - this process is described above in "Automatic iSCSI Optimization".


 

Flow Control

Flow control support is enabled by default on all interfaces and can be configured on a per-interface basis, effective immediately:

 


CLI:

 

1. Login to the CLI and enable flow control on the necessary interfaces - this example configures gigabit interfaces 1-48 on the PowerConnect 5548:

console>enable

console#configure

console(config)#interface range gigabitethernet 1/0/1-48

console(config-if-range)#flowcontrol on

 

2. Save the configuration:

console(config-if-range)#end

console#copy running-config startup-config

 

Overwrite file [startup-config] ?[Yes/press any key for no]....

%COPY-I-FILECPY: Files Copy - source URL running-config destination URL flash://startup-config

%COPY-N-TRAP: The copy operation was completed successfully

Copy succeeded


 

Web UI:

 

1. Navigate to Switching > Ports > Port Configuration > Edit. Select an interface to configure, set Flow Control to "Enable", then click Apply:

2. Save the configuration via System > File Management > Copy Files - this process is described above in "Automatic iSCSI Optimization".

 


Storm Control

The PowerConnect 55xx series switches support broadcast storm control - this feature is disabled by default on all interfaces. If the switch has previously been configured to use broadcast storm control for a non-iSCSI environment, use the following steps to disable broadcast storm control:

 


CLI:

 

1. Login to the CLI and disable broadcast storm control on the necessary interfaces - this example configures gigabit interfaces 1-48 on the PowerConnect 5548:

 

console>enable

console#configure

console(config)#interface range gigabitethernet 1/0/1-48

console(config-if-range)#no storm-control broadcast enable

 

2. Verify that broadcast storm control is disabled:

 

console(config-if-range)#end

console#show storm-control

 

 

Port State Admin Rate Oper Rate [Kbits/Sec] Included

-------- -------- ---------- --------------------- ------------------

gi1/0/1 Disabled 8500 8500 BC

gi1/0/2 Disabled 8500 8500 BC

gi1/0/3 Disabled 8500 8500 BC

...

 

 

3. Save the configuration:

console(config-if-range)#end

console#copy running-config startup-config

 

Overwrite file [startup-config] ?[Yes/press any key for no]....

%COPY-I-FILECPY: Files Copy - source URL running-config destination URL flash://startup-config

%COPY-N-TRAP: The copy operation was completed successfully

Copy succeeded


Web UI:

 

1. After logging into the web UI, navigate to Switching > Ports > Storm Control > Edit. Select an interface to configure, set Broadcast Control to "Disable", then click Apply:

2. After configuring each appropriate interface, select "Summary" to verify that broadcast storm control is disabled:

3. Save the configuration via System > File Management > Copy Files - this process is described above in "Automatic iSCSI Optimization".