Dell PowerConnect 62xx/8024/8024F Switch Configuration

To perform the following configuration steps, the switch must be in “privileged” mode which is enabled using the “enable” command. 

Once the switch is in“privileged” mode, we need to then switch to configuration mode, the following command must be entered:

console# configure
console(config)#

 Interface Naming Convention

Interfaces use the following naming format:

  1. Unit#/Interface ID — each interface is identified by the Unit# followed by a / symbol and then the Interface ID (see below). For example, 2/g10 identifies gigabit port 10 within the second unit of a stack.
  2. Unit# — the unit number is used only in a stacking solution where a number of switches are stacked to form a virtual device. In this case, the unit number identifies the physical device identifier within the stack.
  3. Interface ID — is formed by the interface type followed by the interface number. There is currently a predefined list of interface types (see below). If additional interface types are to be defined, they must be registered with Dell. For example, 2/g10 identifies the gigabit port 10 on the second unit.
  4. Interface Types — the following interface types are defined in the 62xx/8024/8024F series switches:
    • g — gigabit Ethernet port (for example, 1/g2 is the gigabit Ethernet port 2).
    • g — 10 Gigabit Ethernet port (for example, 1/xg2 is the 10 gigabit Ethernet port 2).

PortFast and Spanning-Tree Protocol

Dell recommends that you disable the spanning-tree protocol (STP) on the switch ports that connect end nodes such as iSCSI initiators and SAN interfaces. If you enable STP on those switch ports, then you should turn on the STP FastPort feature to allow fast transition of the ports into the “Forwarding” state.

PortFast immediately transitions the port into STP forwarding mode upon linkup. The port still participates in STP. However, if the port is part of a loop, the port eventually transitions into STP blocking mode.

Note: PowerConnect Switches default to RSTP (Rapid Spanning Tree Protocol) an evolution in STP that provides for faster Spanning tree convergence and is preferable to STP.

To enable the Rapid Spanning Tree Protocol (RSTP) use the command:

console(config)# spanning-tree mode rstp

To enable PortFast, the spanning-tree PortFast command must be used. The following command to enables PortFast on a single port, Port 10 of PC8024 Switch #1 in a stack:

console(config)# interface ethernet 1/xg10
console(config-if-1/xg10)# spanning-tree portfast
console(config-if-1/xg10)# exit

To enable PortFast on all ports in a PowerConnect 62xx/8024/8024F switch stack:

console(config)# interface range ethernet all
console(config-if)# spanning-tree portfast
console(config-if)# exit

Configuring Flow Control

Flow control on the PowerConnect 62xx Family of switches is off by default but Flow Control on the PowerConnect 8024/8024F switches is enabled by default. To enable flow control on all ports in the switch, use the flowcontrol command.

A handy hint if you are connecting an MD32xx, MD36xx or Equalogic series disk array, the storage arrays will autoconfigure to the switch when Flow Control is turned on.

To enable flow control on all ports of a PowerConnect 6248, enter the following commands:

console(config)# flowcontrol
console(config)# exit

Configuring Storm Control

A traffic “storm” occurs when a large outpouring of packets creates excessive network traffic that degrades network performance. Most managed switches have storm control features that prevent ports from being disrupted by broadcast, multicast, or unicast traffic storms on physical interfaces. These features typically work by dropping network packets when the traffic on an interface reaches a percentage of the overall load, sometimes set as high as 80 percent.

Since iSCSI traffic is unicast traffic and can typically utilize the entire link in a high demand environment, it is recommended that you disable unicast storm control on switches that handle iSCSI traffic to prevent any loss of packets. While the use of broadcast and multicast storm control should still be enabled.

To disable unicast and enable multicast/broadcast storm control on a single port – Port 10 of PC6248 Switch #3 in a stack use the following commands:

console(config)# interface ethernet 3/g10
console(config-if-3/g10)# no storm-control unicast
console(config-if-3/g10)# storm-control multicast
console(config-if-3/g10)# storm-control broadcast
console(config-if-3/g10)# exit

To configure the storm control on all ports in a PowerConnect 62xx/8024/8024F switch, use the following:

console(config)# interface range ethernet all
console(config-if)# no storm-control unicast
console(config-if)# storm-control multicast
console(config-if)# storm-control broadcast
console(config-if)# exit

Jumbo Frames

Dell recommends that you enable jumbo frames on the switch ports that handle iSCSI traffic. Jumbo frames are not enabled by default. To enable jumbo frames on the Powerconnect 62xx/8024/8024F switch, use the MTU interface configuration command with a parameter of 9216.

To enable the jumbo frame on one specific port – Port 10 of PC8024 Switch #1 in a stack:

console(config)# interface ethernet 1/xg1
console(config-if-1/xg1)# mtu 9216
console(config-if-1/xg1)# exit

For all ports in a PowerConnect 62xx/8024/8024F switch, use:

console(config)# interface range ethernet all
console(config-if)# mtu 9216
console(config-if)# exit

Jumbo frames must be enabled throughout the entire iSCSI SAN network. That includes NICs, Switches, and storage array ports, otherwise network behaviour may be inconsistent. If jumbo frames are enabled throughout the iSCSI SAN fabric then the Dell PowerVault MD32xxi/MD36xxi and Dell EqualLogic storage arrays will autoconfigure to handle jumbo frames.

Configuring Link Aggregated Group (LAG) for iSCSI use

When you have two or more Ethernet switches for iSCSI traffic it is recommended to a create Link Aggregated Group (LAG) by having Interswitch Links (ISLs) for redundancy, performance and better scalability. This also applies when you are trunking normal ethernet traffic to a server.

The number of connections or Ethernet ports in the LAG per switch should ideally be equal to the number of active Ethernet interfaces on all iSCSI storage arrays connected to the switch. For example, if you have two switches connected to two arrays, and each switch has two active array network connections, the LAG should ideally be an aggregate of at least four Ethernet ports.

Dell states that A stacking bus is recommended if a large number of available ports will be used for the LAG or the available ports are at a premium.

The following steps are an example of how to configure the LAG that consists of four ports – ports 21-24 that are linked between two PowerConnect 8024 switches. It is required to enable the jumbo frames on the LAG.

Switch 1:

console(config)# interface range ethernet 1/xg21-1/xg24
console(config-if)# channel-group 1 mode on
console(config-if)# mtu 9216
console(config-if)# exit
console(config)# interface port-channel 1
console(config-if-ch1)# mtu 9216
console(config-if-ch1)# exit
Switch 2:

console(config)# interface range ethernet 1/xg21-1/xg24
console(config-if)# channel-group 1 mode on
console(config-if)# mtu 9216
console(config-if)# exit
console(config)# interface port-channel 1
console(config-if-ch1)# mtu 9216
console(config-if-ch1)# exit

References:

Advertisements