Switch Performance - switch mode vs router mode

  • 1
  • Question
  • Updated 4 years ago
  • Answered
In a previous question, it was pointed out that when running switches in router mode there is a performance hit because the packets are steered through the CPU. So that begs the question how much of a hit is it?

Does every single packet get steered through the CPU when in router mode or just the packets destined for the WAN?

What is the total throughput of a switch in switch mode vs router mode?

Are there any other drawbacks to using the switches in router mode?

When will we see dynamic routing protocols, like RIP or OSPF?

To give some context, many of my remote sites have an ethernet hand off to our metro ethernet network (Comcast ENS) and I'd like to use the switches on layer 3 so I don't have to manage a separate router.

Would I be better off purchasing a BR200 and hanging switches off of it?

Many Thanks,
Photo of Will Rhodes

Will Rhodes

  • 45 Posts
  • 9 Reply Likes

Posted 4 years ago

  • 1
Photo of Nick Lowe

Nick Lowe, Official Rep

  • 2487 Posts
  • 449 Reply Likes
When basic routing is done properly in switching, it is done in a non-blocking way via TCAM at wirespeed, with copy to CPU only when necessary.

I am certainly interested where things are here as there is incumbent edge switching deployed I am keen to see replaced with something more modern.
Photo of Mike Kouri

Mike Kouri, Official Rep

  • 1026 Posts
  • 269 Reply Likes
If you are looking to deploy this year, buy a BR200 and hang switches off of it.