Utilization Lists for Uplink Ports

An uplink utilization list displays the percentage of a given uplink port bandwidth that is used by a specific list of downlink ports. The percentages are based on 30-second intervals of RMON packet statistics for the ports. Both transmit and receive traffic is counted in each percentage.

Note: This feature is intended for ISP or collocation environments in which downlink ports are dedicated to various customers’ traffic and are isolated from one another. If traffic regularly passes between the downlink ports, the information displayed by the utilization lists does not provide a clear depiction of traffic exchanged by the downlink ports and the uplink port.

Each uplink utilization list consists of the following information:

  • Utilization list number (1, 2, 3, or 4)
  • One or more uplink ports
  • One or more downlink ports

Each list displays the uplink port and the percentage of that port bandwidth that was utilized by the downlink ports over the most recent 30-second interval.

You can configure up to four bandwidth utilization lists.

The following example shows the configuration of a link utilization list with port 1/1/1 as the uplink port and ports 1/1/2 and 1/1/3 as the downlink ports.

device# configure terminal
device(config)# relative-utilization 1 uplink ethernet 1/1/1 downlink ethernet 1/1/2 to 1/1/3 
device(config)# write memory

Displaying Utilization Percentages for an Uplink

After configuring an uplink utilization list, you can use the show relative-utilization command to display the percentage of the uplink bandwidth that each of the downlink ports used during the most recent 30-second port statistics interval. The number of packets sent and received between the two ports is displayed, as well as the ratio of each individual downlink port packets relative to the total number of packets on the uplink.

In the following example, ports 1/1/2 and 1/1/3 are sending traffic to port 1/1/1. Port 1/1/2 and port 1/1/3 are isolated (not shared by multiple clients) and do not exchange traffic with ports other than the uplink port, 1/1/1. For this reason, the percentages for the two downlink ports equal 100%. Cases in which specified the ports exchange traffic with other ports in the system or when the downlink ports are configured together in a port-based VLAN, the percentages may not add up to 100%.

device# show relative-utilization 1  
uplink: ethe 1
30-sec total uplink packet count = 3011
packet count ratio (%)
  1/1/2:60   1/1/3:40

In the following example, ports 1/1/2 and 1/1/3 are in the same port-based VLAN.

device# show relative-utilization 1  
uplink: ethe 1
30-sec total uplink packet count = 3011
packet count ratio (%)
  1/1/2:100   1/1/3:100

In the example below, port 1/1/2 is connected to a hub and is sending traffic to port 1/1/1. Port 1/1/3 is unconnected.

device# show relative-utilization 1  
uplink: ethe 1
30-sec total uplink packet count = 2996
packet count ratio (%)
  1/1/2:100   1/1/3:---