Setup Guide

If there are any additional disruptions, the server does not switch back to the virtual port, and the VM traffic does not follow the
configured device mapping. Note that this behavior can also occur when a VM first boots, prior to any failover.
When this behavior occurs, the VM WWN will be logged in to the fabric. The WWN appears in the output of ag --show and ag --
wwnmapshow, as well as on the switch. The portperfshow command displays all traffic on the port to which the ESX server port is
mapped (base PID).
Configuring device mapping
To configure WWN mapping on VMware ESX systems, use the following steps.
1. Make sure that virtual world wide port names (VWWPNs) of virtual machines (VMs) are mapped to the correct port group (or
N_Port). Brocade recommends that you map all VWWPNs to N_Ports to avoid confusion.
2. Make sure all VWWPNs are mapped for LUN access for array-based targets.
3. Make sure to include all VWWPNs in the zone configuration.
4. Reboot the VM.
5. Zone the physical port on the server to the storage device.
6. Check the traffic that originates from the virtual node PID (VN PID). If the configuration is correct, traffic will flow from the VN
PID.
Failover and failback considerations
When using device mapping with VMware, the base device initiates port login (PLOGI) and process login (PRLI) to the target, and then
discovers the logical unit number (LUN). The virtual device also initiates a PLOGI and PRLI to the target, but LUN discovery does not
occur. Therefore, when the device-mapped port is toggled and failover or failback takes place, traffic resumes from the base device. One
of the following actions is recommended when using device mapping with VMware:
∙ Make sure targets can be reached by the base device so that network traffic can resume if the mapped device fails over and
traffic moves over to the base PID.
∙ Reboot the server so that it initializes and uses configured device mapping.
Considerations for Access Gateway mapping
This section presents considerations and limitations for Access Gateway mode mapping types.
Mapping priority
To avoid problems when both port and device mapping are implemented, AG mode uses a priority system to select the N_Port where a
fabric login (FLOGI) is routed. Access Gateway mode considers mappings in the following order until one can be used.
NOTE
Only NPIV devices can use device mapping and the automatic Device Load Balancing policy. Device Load Balancing policy is
enabled per module rather than per port group.
For more information, refer to Port Grouping policy on page 52.
1. Static device mapping to N_Port (if defined)
2. Device mapping to N_Port group (if defined)
3. Automatic Device Load Balancing within a port group (if enabled)
4. Port mapping to an N_Port
Configuring Ports in Access Gateway Mode
Brocade Fabric OS Access GatewayAdministration Guide
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