system-jumbo-global enable-jumbo

Description                                                    Globally enable jumbo frame support. In this release, a jumbo frame is an Ethernet frame that is more than 1522 bytes long.

NOTE:                                                                   Jumbo frames are not supported on all platforms. For detailed information, refer to the Release Notes.

Syntax                                                                  [no] system-jumbo-global enable-jumbo

NOTE:                                                                   This is the only command required to enable jumbo support on FTA models. See the Usage section below for details on enabling jumbo support on non-FTA mod­els.

Default                                                                Disabled

Mode                                                                   Configuration mode

Usage                                                                  Notes about the usage of this command:

     If your configuration uses VEs, you must enable jumbo on the individual Ethernet ports first, then enable it on the VEs that use the ports. If the VE uses more than port, the MTU on the VE should be the same or smaller than the MTU on each port.

     Enabling jumbo support does not automatically change the MTU on any interfaces. You must explicitly increase the MTU on those interfaces you plan to use for jumbo packets.

     Jumbo support is not recommended on 10/100 Mbps ports.

     On FTA models only, for any incoming jumbo frame, if the outgoing MTU is less than the incoming frame size, the ACOS device fragments the frame into 1500-byte frag­ments, regardless of the MTU set on the outbound interface. If it is less than 1500 bytes, it will be fragmented into the configured MTU.

     Setting the MTU on an interface indirectly sets the frame size of incoming packets to the same value. (This is the maximum receive unit [MRU]).

     In previous releases, the default MTU is 1500 and can not be set to a higher value.

CAUTION:                                                         On non-FTA models, after you enable (or disable) jumbo frame support, you must save the configuration (write memory command) and reboot (reboot com­mand) to place the change into effect.

If jumbo support is enabled on a non-FTA model and you erase the startup-config, the device is rebooted after the configuration is erased.Configuration mode.

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