Enabling Jumbo Frames

Posted on 2009-12-20
Last Modified: 2013-11-14
i would like to enable jumbo frames on my catalyst 2960 for my iscsi storage, it seems that there is no option to only enable jumbo frames for a specific vlan, would enabling it on the entire switch have an adverse effect on the other vlans where the end stations do not have jumbo frames enabled?
Question by:mtatechys
    LVL 68

    Expert Comment


    as far as I know jumbo frames can always be received and processed, by any GE capable interface.

    Enabling jumbo frames only means to enable sending them.



    Author Comment

    my question is if i enable jumbo frames on the switch and i have servers/workstations etc connected to the switch that dont support jumbo frames - will there be any impact on those machines - is there anything i need to be careful with, for example say i had a sql server on the network and its NIC is configured for jumbo frames but the clients arent configured for them what would happen
    LVL 68

    Expert Comment

    As I told you - any station can RECEIVE and process jumbo frames, whether enabled or not.
    Only enabled stations can SEND them.
    Obviously you won't see a performance gain in communications between enabled and non-enabled stations.
    LVL 50

    Expert Comment

    by:Don Johnston
    According to this document:

    "The default maximum transmission unit (MTU) size for frames received        and transmitted on all interfaces on the switch is 1500 bytes."

    "You can        increase the MTU size to support jumbo frames on all Gigabit Ethernet        interfaces with the system mtu jumbo global        configuration command."

    After enabling jumbo frames, you must reload the switch.

    The "show system mtu" command will display if jumbo frames are enabled.
    LVL 16

    Accepted Solution

    You should be find when enabeling jumbo frames. most devices are self limiting so if one station cant support jumbo frams then they will nto be sent for that link. if both ends suport them and they are enabled then they will be used.

    All my core switchs have jumbo frames enabables now and still most traffic is sent using the stnadard 1500 MTU size. only when servers at both ends are enababled do you see jumbo frmaes being sent

    Write Comment

    Please enter a first name

    Please enter a last name

    We will never share this with anyone.

    Featured Post

    Do You Know the 4 Main Threat Actor Types?

    Do you know the main threat actor types? Most attackers fall into one of four categories, each with their own favored tactics, techniques, and procedures.

    Suggested Solutions

    We wanted to provide an in-depth explanation of the Ping Node offering clarifications on its function and usage. Incorrect Ping Node configuration and functionality can cause problems with HA clusters. The importance of this article is critical for …
    Lets start to have a small explanation what is VAAI(vStorage API for Array Integration ) and what are the benefits using it. VAAI is an API framework in VMware that enable some Storage tasks. It first presented in ESXi 4.1, but only after 5.x sup…
    This video teaches viewers how to encrypt an external drive that requires a password to read and edit the drive. All tasks are done in Disk Utility. Plug in the external drive you wish to encrypt: Make sure all previous data on the drive has been …
    This Micro Tutorial will teach you how to reformat your flash drive. Sometimes your flash drive may have issues carrying files so this will completely restore it to manufacturing settings. Make sure to backup all files before reformatting. This w…

    758 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    11 Experts available now in Live!

    Get 1:1 Help Now