Intel 480T, User Manual

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C H A P T E R 4 Configuring Switch Ports
Jumbo Frames
Jumbo frames are Ethernet frames that are larger than 1522 bytes,
including four bytes used for the cyclic redundancy check (CRC).
The 480T switch supports switching and routing of jumbo frames at
wire-speed on all ports.
Jumbo frames are used between endstations that support larger
frame sizes for more efficient transfers of bulk data. Both
endstations involved in the transfer must be capable of supporting
jumbo frames. The switch does not perform IP fragmentation, or
participate in MTU negotiation on behalf of devices that do not
support jumbo frames.
Enabling Jumbo Frames
To enable jumbo frame support, you must configure the maximum
MTU size of a jumbo frame that will be allowed by the switch. To
set the maximum MTU size, use the following command
config jumbo-frame size <jumbo_frame_mtu>
The jumbo_frame_mtu range is 1522 to 9216. The value describes
the maximum size “on the wire,” and includes 4 bytes of CRC plus
another 4 bytes if 802.1Q tagging is being used.
Next, enable support on the physical ports that will carry jumbo
frames, using the following command:
enable jumbo-frame ports [<portlist> | all]
Some network interface cards (NICs) have a configured maximum
MTU size that does not include the additional 4 bytes of CRC.
Ensure that the NIC maximum MRU size is at or below the
maximum MTU size configured on the switch. Frames that are
larger than the MTU size configured on the switch are dropped at
the ingress port.
Load Sharing
Load sharing (Link Aggregation) using 480T switches allows you
to increase bandwidth and resilience between switches by using a
group of ports to carry traffic in parallel between switches. The
sharing algorithm allows the switch to use multiple ports as a single