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Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 4 Configuring Ethernet, Fast Ethernet, Gigabit Ethernet, and 10-Gigabit Ethernet Switching
Setting the Port Configuration
•
The Multilayer Switching Feature Card 2 (MSFC2) supports jumbo frame routing with Cisco IOS
Release 12.1(2)E and later releases.
•
The Multilayer Switching Feature Card (MSFC) and the Multilayer Switch Module (MSM) do not
support jumbo frame routing; if jumbo frames are sent to these routers, router performance is
significantly degraded.
Note
Occasionally, you might see a “Jumbo frames inconsistent state” message for a port or multiple ports
after entering the
show port jumbo
command. If you see this message, enter the
set port jumbo
command to reenable the ports.
To enable jumbo frames on an Ethernet port, perform this task in privileged mode:
This example shows how to enable jumbo frames on a port and verify the configuration:
Console> (enable)
set port jumbo 2/1 enable
Jumbo frames enabled on port 2/1
Console> (enable)
show port jumbo
Jumbo frames MTU size is 9216 bytes
Jumbo frames enabled on port(s) 2/1
To disable jumbo frames on an Ethernet port, perform this task in privileged mode:
This example shows how to disable jumbo frames on a port:
Console> (enable)
set port jumbo 2/1 disable
Jumbo frames disabled on port 2/1
Console> (enable)
Configuring Jumbo Frames on the MSFC2
With an MSFC2, you can configure the MTU size on VLAN interfaces to support jumbo frame routing
.
Jumbo frames support only a single larger-than-default MTU size on the switch. Configuring a VLAN
interface with an MTU size that is greater than the default automatically configures all other VLAN
interfaces that have an MTU size that is greater than the default to the newly configured size. The VLAN
interfaces that have not been changed from the default are not affected.
Task
Command
Step 1
Enable jumbo frames.
set port jumbo
mod
/
port
enable
Step 2
Verify the port configuration.
show port jumbo
Task
Command
Step 1
Disable jumbo frames.
set port jumbo
mod
/
port
disable
Step 2
Verify the port configuration.
show port jumbo