Configuring 2 stacked Cisco 2960s Switches for use with an iSCSI Equallogic PS 4000XV

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Configuring 2 stacked Cisco 2960s Switches for use with an iSCSI Equallogic PS 4000XV

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How do I configure 2 stacked Cisco 2960s Switches for use with an iSCSI Equallogic PS 4000XV?

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  • It's my opinion, but a traditional 'stackable' switch has a very high speed, high bandwidth, redundant bus for the interconnect.   I.e. 3750x.  Which allows multiple switches to be stacked.   On the 2960TS, you are effectively limited to two.  More than that and you lose redundancy and the link becomes ineffective.  Since the 2x 10GbE interconnects would be split between three switches.  A true stack doesn't suffer that issue.  There's no hoping between switches to get to another stack member.

    For a small environment that would be fine to just have the two switches.  

    -don

  • I think you're wrong.  The OP is referring to 2960-S with flexstack modules, not using 2x 10GbE uplink ports.  I do think the limit on flexstack is 20Gbps so in a way it adds up to a similar thing.

    A.W I have a pair of stacked 2960-S running iSCSI.  Just used 802.3AD active/active bonds for the SANs and host based active/passive bonds for hosts (with each port going in to a different switch).  The main limitation on these is the number of port groups (available for active/active bonds) which I seem to remember was around 6?

    Found this recently which may be useful for someone else using these for iSCSI:

    packetlife.net/.../catalyst-2960s-iscsi-optimization

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  • Hello,

    First the 2960 is not a stackable switch.  You will have to create a Channel Group of four ports between them.

    The setup on the switch should be:

     Use a NON default VLAN (VLAN1)    Use something like VLAN 11  

     All the array and server ports should be set to:

        flowcontrol receive desired

        spanning tree pvst

    The jumbo MTU size is 9000

    With that you should be fine.

    -don

  • some kinds of cisco 2960s are stackable switch. e.g. 2960s-24ts-l

  • The 2960 stacking uses the 2x 10GbE ports.   Not what I consider 'stackable' switch.  I.e. the 3750 line which allows a number of switches to be stacked together over a much higher speed bus.   So effectively the 2960 is limited to 2x switches.  

    -don

  • why dont' you think 2960s is a stackable switch? and how about "WS-C2960S-24TS-L" ? it has a stackable module.

  • It's my opinion, but a traditional 'stackable' switch has a very high speed, high bandwidth, redundant bus for the interconnect.   I.e. 3750x.  Which allows multiple switches to be stacked.   On the 2960TS, you are effectively limited to two.  More than that and you lose redundancy and the link becomes ineffective.  Since the 2x 10GbE interconnects would be split between three switches.  A true stack doesn't suffer that issue.  There's no hoping between switches to get to another stack member.

    For a small environment that would be fine to just have the two switches.  

    -don

  • I think you're wrong.  The OP is referring to 2960-S with flexstack modules, not using 2x 10GbE uplink ports.  I do think the limit on flexstack is 20Gbps so in a way it adds up to a similar thing.

    A.W I have a pair of stacked 2960-S running iSCSI.  Just used 802.3AD active/active bonds for the SANs and host based active/passive bonds for hosts (with each port going in to a different switch).  The main limitation on these is the number of port groups (available for active/active bonds) which I seem to remember was around 6?

    Found this recently which may be useful for someone else using these for iSCSI:

    packetlife.net/.../catalyst-2960s-iscsi-optimization

  • Very useful URL, thanks.