KB.15.15

Configuring jumbo frame operation

Overview

1. Determine the VLAN membership of the ports or trunks through which you want the switch to

accept inbound jumbo traffic. For operation with GVRP enabled, refer to the GVRP topic under

“Operating Rules”, above.

2. Ensure that the ports through which you want the switch to receive jumbo frames are operating

at least at gigabit speed. (Check the Mode field in the output for the show interfaces

brief <port-list> command.)

3. Use the jumbo command to enable jumbo frames on one or more VLANs statically configured

in the switch. (All ports belonging to a jumbo-enabled VLAN can receive jumbo frames.

4. Execute write memory to save your configuration changes to the startupconfig file.

Viewing the current jumbo configuration

Syntax

show vlans

Lists the static VLANs configured on the switch and includes a Jumbo column to indicate which

VLANs are configured to support inbound jumbo traffic. All ports belonging to a jumbo-enabled

VLAN can receive jumbo traffic.

Figure 81 Listing of static VLANs to show jumbo status per VLAN

Syntax

show vlans ports<port-list>

Lists the static VLANs to which the specified ports belong, including the Jumbo column to indicate

which VLANs are configured to support jumbo traffic.

Entering only one port in port-list results in a list of all VLANs to which that port belongs.

Entering multiple ports in port-list results in a superset list that includes the VLAN memberships

of all ports in the list, even though the individual ports in the list may belong to different subsets of

the complete VLAN listing.

Example

If port 1 belongs to VLAN 1, port 2 belongs to VLAN 10, and port 3 belongs to VLAN 15, executing

this command with a port-list of 1 - 3 results in a listing of all three VLANs, even though none

of the ports belong to all three VLANS. (See Figure 82.)

Configuring jumbo frame operation 181