Configuring a Dell 6248 Switch Stack for use with a EqualLogic PS4000E Storage Array

I’m going to be doing some write ups over the next few days pertaining to getting a small VMWare vSphere 4.1 installation set up. We’ll be using a pair of Dell 6248 Switches, configured in a stack, and a Dell EqualLogic PS4000E iSCSI Storage Array as our back end. In preparation for that I’m going to be going over our switch and network configuration in this post so that it’s clear as to how the network is configured.

We’ll have vlans for each of the following purposes:

  • Native vlan 1: we’ll use this as our isolated, un-trunked vlan for this switch, the vlan where unconfigured ports are placed by default. (vlan 1)
  • Management: things like DRACs, iLos, UPS management NICs, SAN  Management NICs, etc (vlan 2)
  • vMotion: Moving Virtual machines from one host to another host (vlan 3)
  • HA: VMWare Fault Tolerance (vlan 4)
  • iSCSI traffic (vlan 5)
  • and finally all vlans needed for the production virtual servers (vlans 6 & 7 )
As a perquisite, we’re going to be doing some basic setup of the switch stack, if you’re not setup the switches in a stack yet, please see this post.
Log into the switch and enter the following commands:
  1. switchstack> enable
  2. switchstack# config
  3. switchstack(config)# vlan database
  4. switchstack(config-vlan)# vlan 2-7
  5. switchstack(config-vlan)# exit
  6. switchstack(config)# interface vlan 2
  7. switchstack(config-if-vlan2)# name MGMT_VLAN
  8. switchstack(config-if-vlan2)# exit
  9. repeat steps 6-8 for each vlan, giving each a descriptive name
  10. switchstack(config)# spanning-tree mode rstp (assuming you are using rstp with your other switches in your network)
Now let’s configure some access ports for the MGMT Vlan devices to plug into, we’ll use the last 4 ports on each switch.
  1. switchstack(config)# interface range ethernet 1/g44-1/g48,2/g44-2/g48
  2. switchstack(config-if)# switchport mode access
  3. switchstack(config-if)# switchport access vlan 2
  4. switchstack(config-if)# spanning-tree portfast
  5. switchstack(config-if)# exit
We used spanning-tree portfast because we know these ports will be plugged into end devices, and we want them to come up instantly if the switch is rebooted, or a cable is unplugged and then plugged back in, we don’t want to wait for spanning tree to check for switching loops.

We’ll also need to define a few access ports for vlan 5, where we’ll be plugging in our pS4000E, follow the exact same steps we used above to configure vlan 2, but substitute vlan 5 for vlan 2, make sure you plug the ports 0 and 1 on the EqualLogic Controller Modules into the vlan 5 ports of your switch, and port 2 on your controller modules into the switch ports for vlan 2 (port 2 on the SAN controller module is strictly for management, and therefore should not be on the vlans used for iSCSI traffic). We’ll also need to enable jumbo frames on the on switch ports that will be moving iSCSI traffic, and disable unicast storm control. To do this enter the following commands:

  1. switchstack(config)# interface ethernet 1/g20
  2. switchstack(config-if-1/g20)# mtu 9216
  3. switchstack(config-if-1/g20)# no storm-control unicast
  4. switchstack(config-if-1/g20)# exit
  5. repeat steps 1 – 3 for each port that that connects to a storage array port (only 0 and 1, 2 is for management only)
Note: typically the mtu would be set to 9000, but when you run the “iSCSI enable” option on these switches it’s set to 9216, which is what I’ve chosen to implement here. I’ll update this post in the future if this turns out to be a problem with either the ESXi hosts or the EqualLogic SAN.

Also, I normally would not disable unicast storm-control, but when you enable a iSCSI optimization of the Dell Switches, they do this automatically when a EqualLogic SAN is detected on a port, If anyone has the explanation of why this happens please feel free to share it.

Finally we’ll also need to enable flow control at the switch level, to do this enter the following command:

  1. switchstack(config)# flowcontrol
We’re also going to place this switch into the MGMT_VLAN so that it’s management interface is on the same vlan as everything else we’re going to manage. Enter the following commands:
  1. switchstack(config)# IP Address vlan 2
  2. switchstack(config)# ip address x.x.x.x y.y.y.y
  3. switchstack(config)# ip default-gateway z.z.z.z
Where x.x.x.x is the IP address of your switch on the new vlan, y.y.y.y is your subnet mask, and z.z.z.z is your gateway on the mgmt_vlan.

That’s all of the configuration we’ll need at this point, we’ll now setup the EqualLogic San here, and later we’ll configure the switches for Link Aggregation Groups to handle the connections to our ESXi servers.

3 thoughts on “Configuring a Dell 6248 Switch Stack for use with a EqualLogic PS4000E Storage Array

  1. Pingback: Initial Configuration of a EqualLogic PS Series Storage Array | The Day to Day Findings of an IT Engineer

  2. Pingback: Configuring LAG Groups between Dell 62xx Series Switches and ESXi 4.1 | The Day to Day Findings of an IT Engineer

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