How to Deal With the Bandwidth Utilization Status is Critical in Plesk?

If you’re using Plesk to automate your web hosting, then you may come across few errors from time to time. Some will be critical, others will be generic.

One of the critical messages you’ll receive is the bandwidth utilization status with a critical status.

Here’s what you’ll see in the message:

When you receive this message as a Plesk administrator, you should know that there’s a problem with bandwidth utilization for one the server network interface. The bandwidth utilization has exceeded to a critical level. You can find this information in Advanced Monitoring >> Settings >> Threshold >> Network.

For this error, there might be two underlying reasons, which are:

• The bandwidth load threshold is set excessively low
• The bandwidth load was unexpected and you need to inspect the reasons behind it

How to Find the Reasons Behind the Unexpected Load?

You’d have to access the Advanced Monitoring >> Settings >> Threshold >> Network to learn about the bandwidth utilization threshold values. The values will trigger the alerts you receive.

You need to then make estimation for the current utilization.

For Linux, you can use the isof, iftop, or netstat utilities. For Windows, you can use the TaskManager or Resource Monitor tool. You also have the option of using a third-party tool.

Get the threshold data and investigate further. Follow the steps:

• If you expected the bandwidth load, you need to define the optimal value that are above average. You can adjust threshold at Advanced Monitoring >> Settings >> Threshold
• Again, if you expected the bandwidth load but it damages the server, you need to consider increasing the server network bandwidth.
• If the bandwidth load was unforeseen, then dig deep and carry out more investigations.

You should pay special focus to long network activity spikes. They may mean your network is under some kind of cyber attack. If there was unexpected outgoing traffic from your network, then your server might be spamming other servers. So it might be under the control of hackers and spammers who are using your server as a source of spam.

It’s advised that you use the in-built firewalls for controlling the traffic. For Windows, use the Windows Firewall, for Linux, use iptables firewall, and for Plesk, use Plesk extensions.