When IT departments implement network monitoring tools, they get swarmed with data that they did not have before. This new information gives them the power to act on problems intelligently, oftentimes before they end up affecting end users. The challenge, of course, is to move quickly to identify what issue is causing the problem.

One of the most common problems network monitoring tools are employed to solve are problems with bandwidth. Availability is critical for IT departments of all sizes, and slow bandwidth creates productivity problems and even outages that have a real effect on businesses. Identifying the problems behind bandwidth drains can be difficult, so to help, I’ve put together a list of the five most common causes of sudden traffic spikes.

1. Mail Server Issues

It is not uncommon for a remote mail server to continuously deliver the same email through a company’s servers, even if the target recipient denied acceptance. Incompatibility between the two SMTP implementations creates a sort of endless feedback loop that sees the same email going through the server every five minutes, chewing up bandwidth in the process. The solution involves accessing the target mail server to deny access rights to the remote server.

2. Antivirus

Many of the causes of sudden traffic spikes are security-related, be it malicious traffic, DNS attacks, or sometimes, even the AV itself. Virus scans and software updates distributed inside the LAN are a very common source of traffic spikes, and can be easily dealt with by changing scan settings and performing updates during non-critical business hours.

3. Malicious Traffic

Malware outbreaks and hacking attempts can cause spikes in network traffic, often to either mask other malicious activity or because the malware is attempting to force login to devices.

4. Scheduled Backups

Many backup products are scheduled to run at certain time intervals, or at certain times of day. They also are very network intensive, and if the timing is off, can sop bandwidth during working hours.

5. Remote Backup

Some IT departments opt to use cloud-based tools for backup. While those present certain advantages, one disadvantage is that uploading massive backups to the cloud causes serious load issues. Similar to on-premises backups, these need to be scheduled carefully and performed off-hours.

These are not the only causes of traffic spikes, but it is a good example of common and preventable problems that plague networks. Some problems are more serious and involve hardware failures or router issues, which need to be handled with care and can require spending on new equipment.

In all cases, it is critical for IT departments to establish a baseline for their network traffic so they can understand when it is peaking, and set up appropriate alerts to notify them. Alerting, combined with mapping that identifies where problems are coming from, empowers IT admins to quickly and efficiently troubleshoot most any problem.

Dirk Paessler is CEO and Founder of Paessler AG.