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controlling L2 broadcast


I have layer 2 traffic coming directly on my Broadband RAS from different location in the City. Problem is when there is a broadcast it hits directly to my Broadband RAS and all other sites also gets affected . All sites are in different vlans and having different sub-interfaces on my Broadband RAS . but CPU utilization goes high and RAS is not able to serve the rest .

How should i stop my braodcast reaching my RAS , i want to deploy layer 3 device so that only for 1 site broadcast that side only gets affected ...plz help..

PS -- consider RAS just like router.


Re: controlling L2 broadcast

Hello Pushkar,

On the switch port, you can use the "storm-control" command to control the broadcasts.. This will block unnecessary flooded or broadcast traffic.

on the switch port, (interface config), give the following command:

storm-control broadcast 50

(50 % broadcasts allowed)

this will suppress all the broadcasts, once it reaches the threshold. refer to "storm-control" on CCO for more info

Hope this helps.. all the best.. rate replies if found useful...


Community Member

Re: controlling L2 broadcast

hey i have already done this ..thing is that its not always a broadcast ...multiple request from a single user hits my ERX ( RAS ) and the utilization of RAS goes 100 % and affects rest of the sites. i can't put layer 3 in between because the packets coming are PPPOE packets only understood by RAS and none of the devices in between so it has to come on RAS for first hop. i need to break this multiple request..


Re: controlling L2 broadcast


when you say ERX, does that mean Juniper, Unisphere, or another brand (these are actually the only ones I know of that go by that name, ERX)?

I know that on the Juniper ERX, you can limit the number of active subscribers on a port or on a virtual router.

Let me know which device it is, there might be a way to configure the ERX itself for your purpose.



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