Bandwidth Control

Unanswered Question
Nov 18th, 2008


I have 100Mb Internet Connection and want to split this up on a 'per VLAN' basis.

I.E. Vlan A gets 10Mb, VlanB gets 20Mb etc. etc.

What's the best (easiest!) way of achieving this?

Can this be done on a Layer3 switch or I was considering using a 2811 router?

Kind Regards,


I have this problem too.
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Joseph W. Doherty Tue, 11/18/2008 - 13:10

If your VLANs have unique subnets, it would be relatively easy to split the bandwidth using CBWFQ, at least outbound. Inbound is problematic. (Inbound you can control the bandwidth going into your VLANs, but not easily control how the inbound 100 Mbps connection would be used. That's best accomplished on the other side of the link's outbound.)

L3 switches aren't generally as feature rich as the routers, so even outbound on them could be problematic. However, many support at least policing or rate limiting.


2811, although they have FastEthernet interfaces don't really have the performance to support 100 Mbps. For software routers, you'll might need at 3845 or larger.

dselfridge Wed, 11/19/2008 - 13:07

Thanks Joseph,

I might try rate limiting on the switch first and see how that goes.

Thanks for your help.

Kind Regards,


kelleydeon Sat, 11/22/2008 - 02:39


You're the CBWFQ man! I don't mean to hyjack this thread but I am needing the same thing. Do a search for CBWFQ in all forums and you'll see Joe helping me.

Quick and dumb question for you Joe. If I can only control bandwidth outbound, that would mean when users are downloading stuff... QoS wouldn't give the bandwith to the prioritised vlan?

Joseph W. Doherty Sat, 11/22/2008 - 04:57

See if my last answer to your original post (not this post) answers this question. If not, let me know there.


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