Your browser failed to load CSS style sheets. Your browser or web proxy might not support elliptic-curve TLS

Building network automation solutions

6 week online course

Start now!
back to overview

Impact of CEF accounting

Jozef Janitor wrote a highly relevant comment to my post on CEF accounting: enabling it on a Catalyst switch drastically reduces its performance. The impact of CEF accounting (or other forwarding plane features) depends on switching implementation:
  • There is almost no impact on single-CPU software platforms; the router has to perform CEF lookup anyway and increases the CEF accounting counters on-the-fly;
  • Distributed software platforms are more complex, as the central CPU has to (at the very least) collect the switching statistics.
  • The impact on hardware platforms is dependent on the layer 3 lookup implementation
In the case of a Catalyst 3550 switch, the L3 TCAM it uses to support IP routing, PBR and access-lists is so different from the CEF data structures that IOS has to fall back to software L3 switching to collect CEF accounting data.

No comments:

You don't have to log in to post a comment, but please do provide your real name/URL. Anonymous comments might get deleted.

Sidebar