Monitoring Iscsi Traffic Flows; Application Of Quality Of Service To Iscsi Traffic Flows; Information Monitored In Iscsi Traffic Flows - Dell S4048–ON Configuration Manual

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Monitoring iSCSI Traffic Flows

The switch snoops iSCSI session-establishment and termination packets by installing classifier rules that trap iSCSI protocol packets to the

CPU for examination.

Devices that initiate iSCSI sessions usually use well-known TCP ports 3260 or 860 to contact targets. When you enable iSCSI optimization,

by default the switch identifies IP packets to or from these ports as iSCSI traffic.

You can configure the switch to monitor traffic for additional port numbers or a combination of port number and target IP address, and you

can remove the well-known port numbers from monitoring.

You can configure iSCSI CoS mode. This mode controls whether CoS (dot1p priority) queue assignment and/or packet marking is

performed on iSCSI traffic.

When you enable iSCSI CoS mode, the CoS policy is applied to iSCSI traffic. When you disable iSCSI CoS mode, iSCSI sessions and

connections are still detected and displayed in the status tables, but no CoS policy is applied to iSCSI traffic.

You can configure whether the iSCSI optimization feature uses the VLAN priority or IP DSCP mapping to determine the traffic class queue.

By default, iSCSI flows are assigned to dot1p priority 4. To map incoming iSCSI traffic on an interface to a dot1p priority-queue other than 4,

use the QoS dot1p-priority command (refer to

recommends setting the CoS dot1p priority-queue to 0 (zero).

You can configure whether iSCSI frames are re-marked to contain the configured VLAN priority tag or IP DSCP when forwarded through

On a switch in which a large proportion of traffic is iSCSI, CoS queue assignments may interfere with other network

control-plane traffic, such as ARP or LACP. Balance preferential treatment of iSCSI traffic against the needs of other critical data

in the network.

iSCSI optimization examines the following data in packets and uses the data to track the session and create the classifier entries that

enable QoS treatment.

Initiator's IP Address

Target's IP Address

ISID (Initiator defined session identifier)

Initiator's IQN (iSCSI qualified name)

Target's IQN

Initiator's TCP Port

Target's TCP Port

Connection ID

If no iSCSI traffic is detected for a session during a user-configurable aging period, the session data is cleared.

QoS dot1p Traffic Classification and Queue

Assignment). Dell Networking

iSCSI Optimization