CHAPTER 15

Managing Virtual Interfaces
Thischapter includes the followingsections:
VirtualInterfaces, page 259
VirtualInterface Subscription Management and Error Handling, page 259

Virtual Interfaces

Ina blade server environment, the number of vNICs and vHBAs configurable for a service profile is determined
byadapter capability and the amount of virtual interface (VIF) namespace available on the adapter. In Cisco
UCS,portions of VIF namespace are allotted in chunks called VIFs. Depending on your hardware, the
maxiumumnumber of VIFs are allocated on a predefined, per-port basis.
Themaximum number of VIFs varies based on hardware capability and port connectivity. For each configured
vNICor vHBA, one or two VIFs are allocated.Stand-alone vNICs and vHBAs use one VIF and failover
vNICsand vHBAs use two.
Thefollowing variables affect the number of VIFs available to a blade server, and therefore, how many vNICs
andvHBAs you can configure for a service profile.
• Maximum number of VIFs supported on your fabric interconnect
• How the fabric interconnects are cabled
• If your fabric interconnect and IOM are configured in fabric port channel mode
Formore information about the maximum number of VIFs supported by your hardwareconfiguration, see
CiscoUCS 6100 and 6200 Series Configuration Limits for Cisco UCS Manager for your software release.

Virtual Interface Subscription Management and Error Handling

Forfabric interconnects grouped in a port-channel, changes to the way you connect the fabric interconnect to
theI/O module could result in a drastic change to the number of VIFs available to a blade server. To help you
trackthe effect of these changes, Cisco UCS Manager maintains the following metrics:
• Maximum number of VIFs supported by hardware
• Connectivity type
Cisco UCS Manager GUI Configuration Guide, Release 2.0
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