Autosensing; About Interface Descriptions; About Frame Encapsulation; About Receive Data Field Size - HP Cisco MDS 9216 - Fabric Switch Configuration Manual

Chapter 20 Configuring Interfaces
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

Autosensing

Autosensing speed is enabled on all 4-Gbps switching module interfaces by default. This configuration
enables the interfaces to operate at speeds of 1 Gbps, 2 Gbps, or 4 Gbps on the 4-Gbps switching
modules. When autosensing is enabled for an interface operating in dedicated rate mode, 4-Gbps of
bandwidth is reserved, even if the port negotiates at an operating speed of 1-Gbps or 2-Gbps.
To avoid wasting unused bandwidth on 48-port and 24-port 4-Gbps Fibre Channel switching modules,
you can specify that only 2 Gbps of required bandwidth be reserved, not the default of 4 Gbps. This
feature shares the unused bandwidth within the port group provided that it does not exceed the rate limit
configuration for the port. You can also use this feature for shared rate ports that are configured for
autosensing.
When migrating a host that supports up to 2-Gbps traffic (that is, not 4-Gbps with autosensing
Tip
capabilities) to the 4-Gbps switching modules, use autosensing with a maximum bandwidth of 2-Gbps.

About Interface Descriptions

Interface descriptions should help you identify the traffic or use for that interface. The interface
description can be any alphanumeric string.

About Frame Encapsulation

You can set the frame format to EISL for all frames transmitted by the interface in SD port mode. If you
sent the frame encapsulation to EISL, all outgoing frames are transmitted in the EISL frame format,
irrespective of the SPAN source(s). See the
page
Refer to the Cisco MDS 9000 Family CLI Configuration Guide to configure frame encapsulation on an
interface.

About Receive Data Field Size

You can also configure the receive data field size for Fibre Channel interfaces. If the default data field
size is 2112 bytes, the frame length will be 2148 bytes.

Configuring Receive Data Field Size

You can also configure the receive data field size for Fibre Channel interfaces. If the default data field
size is 2112 bytes, the frame length will be 2148 bytes.
To configure the receive data field size using Fabric Manager, follow these steps:
Expand Switches > Interfaces and then select FC Physical.
Step 1
You see the interface configuration in the Information pane.
Click the Other tab and set the RxDataFieldSize field (see
Step 2
OL-16184-01, Cisco MDS SAN-OS Release 3.x
62-1.
"Monitoring Network Traffic Using SPAN" section on
Figure 20-4).
Cisco MDS 9000 Family CLI Configuration Guide
Fibre Channel Interfaces
20-13