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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
CoS dot1p-priority
command (refer to
QoS dot1p Traffic Classification and Queue Assignment
Networking 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 the switch.
NOTE: 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.
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.
If more than 256 simultaneous sessions are logged continuously, the following message displays indicating the queue rate limit has
been reached:
%STKUNIT2-M:CP %iSCSI-5-ISCSI_OPT_MAX_SESS_EXCEEDED: New iSCSI Session Ignored: ISID -
400001370000 InitiatorName - iqn.1991-05.com.microsoft:dt-brcd-cna-2 TargetName -
iqn.2001-05.com.equallogic:4-52aed6-b90d9446c-162466364804fa49-wj-v1 TSIH - 0"
NOTE: If you are using EqualLogic or Compellent storage arrays, more than 256 simultaneous iSCSI sessions are
possible. However, iSCSI session monitoring is not capable of monitoring more than 256 simultaneous iSCSI sessions. If
this number is exceeded, sessions may display as
unknown
in session monitoring output. Dell Networking recommends
that you disable iSCSI session monitoring for EqualLogic and Compellent storage arrays or for installations with more
than 256 simultaneous iSCSI sessions.
Only sessions the switch observes are learned; sessions flowing through an adjacent switch are not learned. Session monitoring
learns sessions that actually flow through the switch, it does not learn all sessions in the entire topology.
After a switch is reloaded, any information exchanged during the initial handshake is not available. If the switch picks up the
communication after reloading, it would detect a session was in progress but could not obtain complete information for it. Any
incomplete information of this type would not be available in the
show
commands.
Detection and Auto-Configuration for Dell EqualLogic Arrays
The iSCSI optimization feature includes auto-provisioning support with the ability to detect directly connected Dell EqualLogic
storage arrays and automatically reconfigure the switch to enhance storage traffic flows.
The switch uses the link layer discovery protocol (LLDP) to discover Dell EqualLogic devices on the network. LLDP is enabled by
default. For more information about LLDP, refer to
Link Layer Discovery Protocol (LLDP)
.
iSCSI Optimization
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Содержание S4048-ON
Страница 1: ...Dell Configuration Guide for the S4048 ON System 9 9 0 0 ...
Страница 146: ...Figure 14 BFD Three Way Handshake State Changes 146 Bidirectional Forwarding Detection BFD ...
Страница 477: ...Figure 68 Inspecting Configuration of LAG 10 on ALPHA Link Aggregation Control Protocol LACP 477 ...
Страница 480: ...Figure 70 Inspecting a LAG Port on BRAVO Using the show interface Command 480 Link Aggregation Control Protocol LACP ...
Страница 481: ...Figure 71 Inspecting LAG 10 Using the show interfaces port channel Command Link Aggregation Control Protocol LACP 481 ...
Страница 522: ...Figure 87 Configuring Interfaces for MSDP 522 Multicast Source Discovery Protocol MSDP ...
Страница 523: ...Figure 88 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 523 ...
Страница 524: ...Figure 89 Configuring PIM in Multiple Routing Domains 524 Multicast Source Discovery Protocol MSDP ...
Страница 528: ...Figure 91 MSDP Default Peer Scenario 1 528 Multicast Source Discovery Protocol MSDP ...
Страница 529: ...Figure 92 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 529 ...
Страница 530: ...Figure 93 MSDP Default Peer Scenario 3 530 Multicast Source Discovery Protocol MSDP ...
Страница 633: ...Policy based Routing PBR 633 ...
Страница 777: ...Figure 119 Single and Double Tag TPID Match Service Provider Bridging 777 ...
Страница 778: ...Figure 120 Single and Double Tag First byte TPID Match 778 Service Provider Bridging ...