6.0.1

Table Of Contents
Managing iSCSI Network
Special consideration apply to network adapters, both physical and VMkernel, that are associated with an
iSCSI adapter.
After you create network connections for iSCSI, an iSCSI indicator on a number of Networking dialog boxes
becomes enabled. This indicator shows that a particular virtual or physical network adapter is iSCSI-bound.
To avoid disruptions in iSCSI trac, follow these guidelines and considerations when managing iSCSI-
bound virtual and physical network adapters:
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Make sure that the VMkernel network adapters are assigned addresses on the same subnet as the iSCSI
storage portal they connect to.
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iSCSI adapters using VMkernel adapters are not able to connect to iSCSI ports on dierent subnets,
even if those ports are discovered by the iSCSI adapters.
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When using separate vSphere switches to connect physical network adapters and VMkernel adapters,
make sure that the vSphere switches connect to dierent IP subnets.
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If VMkernel adapters are on the same subnet, they must connect to a single vSwitch.
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If you migrate VMkernel adapters to a dierent vSphere switch, move associated physical adapters.
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Do not make conguration changes to iSCSI-bound VMkernel adapters or physical network adapters.
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Do not make changes that might break association of VMkernel adapters and physical network
adapters. You can break the association if you remove one of the adapters or the vSphere switch that
connects them, or change the 1:1 network policy for their connection.
iSCSI Network Troubleshooting
A warning sign indicates non-compliant port group policy for an iSCSI-bound VMkernel adapter.
Problem
The VMkernel adapter's port group policy is considered non-compliant in the following cases:
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The VMkernel adapter is not connected to an active physical network adapter.
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The VMkernel adapter is connected to more than one physical network adapter.
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The VMkernel adapter is connected to one or more standby physical adapters.
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The active physical adapter is changed.
Solution
Follow the steps in “Change Network Policy for iSCSI,” on page 93 to set up the correct network policy for
the iSCSI-bound VMkernel adapter.
Using Jumbo Frames with iSCSI
ESXi supports the use of Jumbo Frames with iSCSI.
Jumbo Frames are Ethernet frames with the size that exceeds 1500 Bytes. The maximum transmission unit
(MTU) parameter is typically used to measure the size of Jumbo Frames. ESXi allows Jumbo Frames with
the MTU up to 9000 Bytes.
When you use Jumbo Frames for iSCSI trac, the following considerations apply:
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The network must support Jumbo Frames end-to-end for Jumbo Frames to be eective.
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Check with your vendors to ensure your physical NICs and iSCSI HBAs support Jumbo Frames.
Chapter 10 Configuring iSCSI Adapters and Storage
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