Why don't I ever see interface fully utilized i.e 255/255

[carl_townshend]

Hi Guys

I have noticed during periods of peak congestion, I never see the interface fully utilised, i.e when I do a show interface, its always around 244/255 and never 255/255.

Would this be because the router upstream may be dropping packets first or something?

Cheers

[M02@rt37]

Hello @carl_townshend,

If the router's upstream link is saturated or experiencing congestion, it might start dropping packets before they even reach your local interface, which can result in the utilization not reaching the maximum value. Monitoring other metrics like packet drops and queue lengths could provide more insights into the exact cause of the observed behavior.

With #show interface X/X command do you see something?

You can use this command to gather data about the interface's performance and identify any issues such as congestion, errors, drops, or other anomalies that might be affecting its operation.

[Joseph W. Doherty]

Dropping packets might be part of the issue.

You're aware of TCP's classic saw tooth bandwidth usage?

It also might be the Cisco router is counting L3 bps not L2 bps.