CPU Impact of "debug ip packet" on Cisco Switches in terms of CPU consumption and possible traffic disruption, what should I generally expect when I run the command: `Switch#debug ip packet` on a Cisco device in a large ISP network? Cisco devices in question: * Catalyst 3750 Series * Catalyst 6500 Series * Catalyst 4500 series * Cisco 7600 Series Routers These device are usually processing no less than 8 Gbps of traffic.

The platforms you mention are all hardware forwarding devices. What debug ip packet does is to show packets going to / from the switch's CPU (either punted, locally-sourced, or control-plane).

You should only see control plane packets here or packets being punted due to a feature being misconfigured or not supported.

People sometimes turn off CEF to debug but this is not recommended and not even supported on some of the platforms such as 3750.

The impact depends on how much traffic you have going to the CPU but it's a risky command to run.

Why do you want to run it? What are you looking for? Have you considered using other methods such as Netflow, SPAN, ERSPAN?

If you really want to debug then log to a buffer, turn off terminal monitoring and combine debug ip packet with an ACL to define which traffic you are interested in. Do so at your own risk though.