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Table Of Contents
Best Practices for Configuring Networking with Software iSCSI
When you configure networking with software iSCSI, consider several best practices.
Software iSCSI Port Binding
You can bind the software iSCSI initiator on the ESXi host to a single or multiple VMkernel ports, so that
iSCSI traffic flows only through the bound ports. When port binding is configured, the iSCSI initiator
creates iSCSI sessions from all bound ports to all configured target portals.
See the following examples.
VMkernel Ports Target Portals iSCSI Sessions
2 bound VMkernel ports 2 target portals 4 sessions (2 x 2)
4 bound VMkernel ports 1 target portal 4 sessions (4 x 1)
2 bound VMkernel ports 4 target portals 8 sessions (2 x 4)
Note Make sure that all target portals are reachable from all VMkernel ports when port binding is used.
Otherwise, iSCSI sessions might fail to create. As a result, the rescan operation might take longer than
expected.
No Port Binding
If you do not use port binding, the ESXi networking layer selects the best VMkernel port based on its
routing table. The host uses the port to create an iSCSI session with the target portal. Without the port
binding, only one session per each target portal is created.
See the following examples.
VMkernel Ports Target Portals iSCSI Sessions
2 unbound VMkernel ports 2 target portals 2 sessions
4 unbound VMkernel ports 1 target portal 1 session
2 unbound VMkernel ports 4 target portals 4 sessions
Software iSCSI Multipathing
Example 1. Multiple paths for an iSCSI target with a single network portal
If your target has only one network portal, you can create multiple paths to the target by adding multiple
VMkernel ports on your ESXi host and binding them to the iSCSI initiator.
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