es) CPU percent per hour (last 72 hours) Here is the output from the show process cpu history command on switch B, which shows 0-3 percent CPU utilization over the course of the last minute (the remaining graphs have been removed for brevity): 3550-IOS# sho proc cpu history 11111 33333 11111 Chapter 8: Spanning Tree CPU% per second (last 60 seconds) The numbers on the left side of the graph are the CPU utilization percentages. The numbers on the bottom are seconds in the past (0 = the time of command execution). The numbers on the top of the graph show the integer values of CPU uti- lization for that time period on the graph. For example, according to the graph above, CPU utilization was normally 0 percent, but increased to 1 percent 5 seconds ago, and 3 percent 20 seconds ago. When the values exceed 10 percent, visual peaks will be seen in the graph itself. This switch is a 3550, and has EIGRP neighbors, SO it's an important device that is providing layer-3 functionality: 3550-IOS# sho ip eigrp neighbors IP-EIGRP neighbors for process 55 H Address Interface Hold Uptime RTO 0 Seq Type (sec) 10.55.1.10 Fa0/13 14 00:25:30 10.55.10.3 13 1wod Now I'll turn up interface F0/14 as a trunk: 3550-I0S(config)# int fo/14 3550-IOS $(config-if)# switchport 3550-IOS (config-if)# switchport trunk encapsulation dot1q 3550-IOS (config-if)# switchport mode trunk There are now two trunks connecting Switch A and Switch B. Remember that I've disabled spanning tree. Mere seconds after I converted F0/14 to a trunk, the input and output rates on F0/15 have shot up from 1,000 bits per second and 2-3 packets per second to 815,000 bits per second and 1,561 packets per second: 3550-IOS# sho int fo/15 I include minute minute input rate 815000 bits/sec, 1565 packets/sec 5 minute output rate 812000 bits/sec, 1561 packets/sec Ten seconds later, the input and output have more than doubled to 2.7 Mbps and 4,500+ packets per second: 3550-IOS# - sho int fo/15 I include minute 5 minute input rate 2744000 bits/sec, 4591 packets/sec 5 minute output ra