Chapter 9 Troubleshooting N-Port Virtualization; Overview - Cisco 9134 - MDS Multilayer Fabric Switch Troubleshooting Manual

S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m
Troubleshooting N-Port Virtualization
This chapter describes how to identify and resolve problems that can occur with N-Port virtualization.
It includes the following sections:
•
•
•

Overview

N-Port virtualization (NPV) reduces the number of Fibre Channel domain IDs in SANs. Switches
operating in the NPV mode do not join a fabric; rather, they pass traffic between NPV core switch links
and end-devices, which eliminates the domain IDs for these edge switches.
NPV is available only for the following Cisco MDS 9000 switches: the Cisco MDS 9124 Multilayer
Note
Fabric Switch, the Cisco MDS 9134 Fabric Switch, the Cisco Fabric Switch for HP c-Class BladeSystem
and the Cisco Fabric Switch for IBM BladeCenter.
NPV makes a Fabric or Blade switch appear as a host to the core Fibre Channel switch, and as a Fibre
Channel switch to the servers in the Fabric or Blade switch. NPV aggregates multiple locally-connected
N-ports into one or more external NP links, thereby sharing the domain ID of the NPV core switch
among multiple NPV switches. NPV also allows multiple devices to attach to same port on the NPV core
switch.
NPV makes use of N port identifier virtualization (NPIV) to get multiple FCIDs allocated from the core
switch on the NP-port.
A switch is in NPV mode after a user has enabled NPV and the switch has successfully rebooted. NPV
mode applies to an entire switch. All end devices connected to a switch that is in NPV mode must log in
as an N-port to utilize this feature (loop-attached devices are not supported). All links from the edge
switches (in NPV mode) to the NPV core switches are established as NP-ports. NPIV is used by the
switches in NPV mode to log in to multiple end-devices that share a link to the NPV core switch.
For a complete description of NPV, refer to the Cisco MDS 9000 Family CLI Configuration Guide.
OL-9285-05
Overview, page 9-1
Initial Troubleshooting Checklist, page 9-2
Common Problems with NPV, page 9-4
C H A P T E R
Cisco MDS 9000 Family Troubleshooting Guide, Release 3.x
9
9-1