Extreme Networks ExtremeWare XOS 11.3, Manual

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Configuring Slots and Ports on a Switch
ExtremeWare XOS 11.3 Concepts Guide
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Jumbo Frames
Jumbo frames are Ethernet frames that are larger than 1522 bytes, including four bytes used for the cyclic
redundancy check (CRC). Extreme products support switching and routing of jumbo frames at wire-
speed on all ports. The configuration for jumbo frames is saved across reboots of the switch.
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 only performs IP fragmentation, or participates in maximum transmission unit (MTU)
negotiation on behalf of devices that support jumbo frames.
You need jumbo frames when running the Extreme Networks VMAN implementation. When you are
working on the BlackDiamond 10K switch, the switch enables jumbo frames when you configure
VMANs. If you are working on the BlackDiamond 8800 family of switches, you enable jumbo frames
for the entire switch prior to configuring VMANs. For more information on configuring VMANs, refer
to
Chapter 9 .
Refer to “Displaying Port Configuration Information” for information on displaying jumbo frame status.
Jumbo Frames on the BlackDiamond 8800 Family of Switches
and Summit X450 Switch Only
The following information applies to jumbo frames on the BlackDiamond 8800 family of switches and
the Summit X450 switch:
●
The BlackDiamond 8800 family of switches and the Summit X450 switch support jumbo frames on
the entire switch; you cannot enable or disable jumbo frames per port.
The BlackDiamond 8800 family of switches and the Summit X450 switch enable or disable jumbo
frames on the entire switch; jumbo frames are either enabled or disabled on every port on the
switch. The system returns an error message if you attempt to enter specified ports.
●
To enable jumbo frame support on the BlackDiamond 8800 family of switches or the Summit X450
switch, use the following command:
enable jumbo-frame ports all
Once you issue this command, any new modules you add to the switch will also have jumbo frames
enabled.
●
When you configure VMANs on the BlackDiamond 8800 family of switches and the Summit X450
switch, you must enable jumbo frames for the entire switches prior to configuring the VMANs.
Enabling Jumbo Frames
NOTE
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 MTU 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.
To enable jumbo frame support, enable jumbo frames on the desired ports. To set the maximum jumbo
frame size, use the following command: