How to limit speed of Cisco Switch 3750G, optical  port

Posted on 2011-04-21
Last Modified: 2012-05-11

I have a 3750G cisco switch, with 24 ethernet port + 4 optical port

I tested OK limit speed on Ethernet port, with speed command, for example:
speed 10 # limit 10 mbis/s

But this command not effect on optical-port
So, how to litmit speed on optical port?

Thank you!

Question by:redstar01
    LVL 35

    Accepted Solution

    Not sure if this works on SFP/optical ports, but you could try:
    srr-queue bandwidth limit weight1

    Here weight1 is a percentage of the total bandwidth.
    LVL 10

    Assisted Solution

    LVL 17

    Assisted Solution

    srr-queue command is only not applicable for 10gig ethernet interfaces. For the rest it should work. Hopefully on optical as well.
    srr-queue command never works ideally because the speed is determined bu the hardware line cards. So if you need exactly X meg traffic it might be X+-few meg.

    srr-queue works on egress traffic. So you might need policing for inbound. (although if egress is dropped the ingress flow reduces automatically).

    Below is the config,

    mls qos -->in global config mode
    policy-map police-Xmb
    class class-default
    police <type value> bc <type value> exceed-action drop

    int  x/y
    srr-queue bandwidth limit Z
    service-policy input police-Xmb


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