NOTE: By default, CAM allocation for iSCSI is set to 0. This disables session monitoring.
Synchronizing iSCSI Sessions Learned on VLT-Lags with VLT-Peer
The following behavior occurs during synchronization of iSCSI sessions.
• If the iSCSI login request packet is received on a port belonging to a VLT lag, the information is synced
to the VLT peer and the connection is associated with this interface.
• Additional updates to connections (including aging updates) that are learnt on VLT lag members are
synced to the peer.
• When receiving an iSCSI login request on a non-VLT interface followed by a response from a VLT
interface, the session is not synced since it is initially learnt on a non-VLT interface through the
request packet.
• The peer that sees the login response packet generates a new connection log. If the login response
packet uses the ICL path, it is seen by both the peers, which in turn generate logs for this connection.
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.
Information Monitored in iSCSI Traffic Flows
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
• Aging
• Up Time
If no iSCSI traffic is detected for a session during a user-configurable aging period, the session data is
cleared.
iSCSI Optimization 485