CCDA: Is Your Network Healthy?

So many students have written me excited for the upcoming Cisco Certified Design Associate (CCDA) 5 day online bootcamp. In this blog post I want to provide everyone with a preview of some of the hugely valuable content in this course.

Early in the week of the event, we review a network health checklist from Cisco Systems. We take this one step further during the bootcamp  and show you how to actually obtain these measurements without breaking your budget:

• Ethernet segments should not feature a sustained utilization of 40% or higher
• All Ethernet segments should be switched - no shared segments (hub-based)
• No WAN links should feature a sustained utilization of 70% or higher
• Response times should be generally less than 100 ms
• LAN response times should generally be 2 ms

• No segments should have more than one CRC (cyclic redundancy check) error per million bytes of data
• No segments should have more than 20 percent multicast or broadcast traffic
• For Ethernet segments, there should be less than .1 percent collisions
• Over 5 minute intervals, CPU utilization should not exceed 75%
• The number of output queue drops should not exceed 100 in an hour
• The number of input queue drops should not exceed 50 in an hour
• The number of buffer misses should not exceed 25 in an hour
• The number of ignored packets should not exceed 10 in an hour