Administrator Guide

iSCSI Optimization 577
How Does iSCSI Optimization Interact With Dell EqualLogic Arrays?
The iSCSI feature includes auto-provisioning support with the ability to
detect directly connected Dell EqualLogic (EQL) SAN storage arrays and
automatically reconfigure the switch to enhance storage traffic flows.
The Dell Networking N-Series switches use LLDP, a vendor-neutral protocol,
to discover Dell EQL devices on the network. LLDP is enabled by default. For
more information about LLDP, see "Discovering Network Devices " on
page 825.
When the switch detects a Dell EQL array, the following actions occur:
• An MTU of 9216 is enabled on the system, if it is not already enabled.
• Spanning tree portfast is enabled on the EQL-connected interface
identified by LLDP.
• Unicast storm control is disabled on the EQL-connected interface
identified by LLDP.
It is advisable to enable spanning tree portfast and disable unicast storm
control on ports connected to the initiators as well.
If the iSCSI CoS policy feature is enabled on the switch and an EQL array is
detected, the switch applies additional iSCSI CoS policies to the EQL inter-
array traffic on TCP ports 9876 and 25555. If the iSCSI CoS policy is disabled
and EQL arrays are present, the additional CoS policy is removed globally.
How Does iSCSI Optimization Interact with Dell Compellent Arrays?
Dell Networking N-Series switches support a macro that may be used to
configure a port connected to a Dell Compellent storage array. The name of
the macro is
profile-compellent-nas . The macro takes a single argument: the
interface identifier to which the Dell Compellent array is connected. The
macro disables unicast storm control and sets the spanning tree configuration
on the port to portfast. For an example of how to execute the macro, see
"Configuring iSCSI Optimization Between Servers and a Disk Array " on
page 587.