3850: routing w/lan based license. Slower than IP based license?

[stratton22]

   We have a few 3850's( w/lan based license )  in various buildings on campus that connect back to our core with 10Gb uplinks. We'd like to make a change so that each building is now a layer 3 boundary and use the 3850 to route by adding a static route to send things to the core.   We're being advised to buy an IP based license for each 3850 as it will allow the 3850  to route the packets in hardware at very significantly faster speeds than the current lan based license would.  

The claim is with a lan based license on the 3850 the CPU is involved with routing and hence much slower. With a IP based license most routing is handled by hardware. I can't seem to find much info on this claim one way or the other.   We have no need for any of the advanced routing features an IP based licence offers.

[Philip D'Ath]

The 3850 will not route packets faster with an "IP base" licence than "LAN base".

All the licence does is add features, not performance.

[stratton22]

Thx for the feedback. I have to be really sure about this.   The advice we are being given is from our Cisco partner and they were pretty persistent in claiming we would not be happy with just a lan based license.  I'm hoping they are just mistaken in what they claim.

Instead of me "proving a negative" I should probably ask them to support their claim...

[Philip D'Ath]

Yes.  Ask them for a Cisco web page indicating their is any relationship between the licence and performance.

There is no such document, because it is not true.

[stratton22]

Sorry for the long delay but I do want to follow up.

As predicted the 3850s hum right along when doing static routing. No cpu issues w/800+ wks on the wire...

Thx to all for the feedback. It did help us have confidence in going forward..

[Philip D'Ath]

Why don't you test it yourself.

Setup two test VLANs doing routing, and run iperf3 between two connected machines.

Windows machine should get 80% to 90% of the link speed.  Linux usually gets 90% to 95%.

You should observe no change on the 3850 CPU while doing the test, indicating that the CPU is not involved in the forwarding path.

[stratton22]

I like it..   Project for next week.   Thx again....