Port Mtu Size - Cisco 7206 - VXR Router Configuration Manual

Information About the Basic Interface Parameters
S e n d d o c u m e n t c o m m e n t s t o n e x u s 7 k - d o c f e e d b a c k @ c i s c o . c o m
Table 2-3
Port Flow Control States
Port Receiving Data
(Sends Pause Frames)
Enabled
Enabled
Enabled
Desired
Desired
Desired
Disabled
Disabled
Disabled
For information on setting the flow-control parameters, see the
on page

Port MTU Size

The maximum transmission unit (MTU) size specifies the maximum frame size that an Ethernet port can
process. For transmissions to occur between two ports, you must configure the same MTU size for both
ports. A port drops any frames that exceed its MTU size.
By default, each port has an MTU of 1500 bytes, which is the IEEE 802.3 standard for Ethernet frames.
Larger MTU sizes are possible for more efficient processing of data with less overhead. The larger
frames, called jumbo frames, can be up to 9216 bytes in size, which is also the default system jumbo
MTU size.
On a Layer 3 interface, you can configure an MTU size between 576 and 9216 bytes. You can configure
up to 64 MTU settings for each I/O module.
The global LAN port MTU size applies to the traffic through a Layer 3 Ethernet LAN port that is
Note
configured with a nondefault MTU size.
For a Layer 2 port, you can configure an MTU size that is either the system default (1500 bytes) or the
system jumbo MTU size (initially 9216 bytes).
If you change the system jumbo MTU size, Layer 2 ports automatically use the system default MTU size
Note
(1500 bytes) unless you specify the new system jumbo MTU size for some or all of those ports.
For information on setting the MTU size, see the
Cisco Nexus 7000 Series NX-OS Interfaces Configuration Guide, Release 5.x
2-6
Port Flow-Control Influences on Link Flow Control
Port Transmitting Data
(Receives Pause Frames)
Enabled
Desired
Disabled
Enabled
Desired
Disabled
Enabled
Desired
Disabled
2-30.
Chapter 2 Configuring Basic Interface Parameters
Link Flow
Control State
Enabled
Enabled
Disabled
Enabled
Enabled
Disabled
Disabled
Disabled
Disabled
"Configuring the Flow Control" section
"Configuring the MTU Size" section on page 2-31.
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