Netflow does not work on compress stac

[rakeshbathija]

I have put compression on one serial interface of 2600 router,netflow does not monitor that interface.is there any way so that it will be to monitor it.Netflow shows statistics of all other interface . when ever we use this command 'show ip cache flow' it shows all the interfaces except the interface where compression is on.

[bbaley]

For efficiency, netflow only counts packets which are fast-switched or CEF-switched through the router.

Since the STAC compression/decompression algorithms are so CPU intensive, packets arriving on compressed interfaces cannot take the fast path through the router and must be process switched.What you are seeing is normal for traffic passing through the compressed interfaces.