Users Guide

If you enable iSCSI, flow control is automatically enabled on all interfaces. To disable flow control on all interfaces, use the no flow
control rx on tx off command and save the configuration. To disable iSCSI optimization, which can turn on flow control again on
reboot, use the no iscsi enable command and save the configuration.
When you enable iSCSI on the switch, the following actions occur:
• Link-level flow control is globally enabled, if it is not already enabled, and PFC is disabled.
• iSCSI session snooping is enabled.
• iSCSI LLDP monitoring starts to automatically detect EqualLogic arrays.
The following message displays when you enable iSCSI on a switch and describes the configuration changes that are automatically
performed:
%STKUNIT0-M:CP %IFMGR-5-IFM_ISCSI_ENABLE: iSCSI has been enabled causing flow control to be
enabled on all interfaces. EQL detection and enabling iscsi profile-compellent on an interface
may cause some automatic configurations to occur like jumbo frames on all ports and no storm
control and spanning tree port-fast on the port of detection.
You can reconfigure any of the auto-provisioned configuration settings that result when you enable iSCSI on a switch.
When you disable the iSCSI feature, iSCSI resources are released and the detection of EqualLogic arrays using LLDP is disabled. Disabling
iSCSI does not remove the MTU, flow control, portfast, or storm control configuration applied as a result of enabling iSCSI.
NOTE: By default, CAM allocation for iSCSI is set to 0. This disables session monitoring.
Default iSCSI Optimization Values
The following table lists the default values for the iSCSI optimization feature.
Table 42. iSCSI Optimization Defaults
Parameter Default Value
iSCSI Optimization global setting Disabled on the S4810, S4820T, S3048–ON, S4048–ON, and
S3100 series.
iSCSI CoS mode (802.1p priority queue mapping) dot1p priority 4 without the remark setting when you enable
iSCSI. If you do not enable iSCSI, this feature is disabled.
iSCSI CoS Packet classification When you enable iSCSI, iSCSI packets are queued based on dot1p,
instead of DSCP values.
VLAN priority tag iSCSI flows are assigned by default to dot1p priority 4 without the
remark setting.
DSCP None: user-configurable.
Remark Not configured.
iSCSI session aging time 10 minutes
iSCSI optimization target ports iSCSI well-known ports 3260 and 860 are configured as default
(with no IP address or name) but can be removed as any other
configured target.
iSCSI session monitoring Disabled. The CAM allocation for iSCSI is set to zero (0).
iSCSI Optimization Prerequisites
The following are iSCSI optimization prerequisites.
• iSCSI optimization requires LLDP on the switch. LLDP is enabled by default (refer to Link Layer Discovery Protocol (LLDP)).
• iSCSI optimization requires configuring two ingress ACL groups The ACL groups are allocated after iSCSI Optimization is configured.
iSCSI Optimization
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