How to Monitor Network Traffic on Your Network?

Network traffic monitoring is essential if you want to be safe and efficient. The information captured by the network traffic monitoring tools can be used in multiple cases of security use and IT operations to identify security vulnerabilities, troubleshoot network problems and analyze the impact of new applications on the network. It can be used. These five tips will help you make the most of your network traffic monitoring application.

1.   Choose the right data source

Whatever your motivation to  network traffic monitor, you can choose between two primary data sources:

Flow data: It can be obtained from a layer 3 device, such as a router

Packet data: It can be obtained from SPAN, mirror port or TAP

The flow data is excellent when looking for the volume of traffic and allocates the movement of the network packets from the source to the destination. This level of information can help detect dishonest WAN traffic and take advantage of network resources and performance. However, flow-based tools to monitor network traffic do not have detailed data to identify many network security problems or perform a real root cause analysis.

The packet data removed from the network packages help network administrators appreciate how users implement and control applications, track the use of WAN links and monitor apprehensive malware and other security incidents. The deep packet inspection tool transforms raw metadata into a readable format that allows network administrators to delve into the details, providing 100% visibility of the entire network.

2.   Pick the correct points on the web to monitor

Of course, agent-based software requires that you install the software on each device you wish to follow. This is not only an expensive way to monitor network traffic but also carries a significant implementation and maintenance overhead to the IT team. Also, if the purpose is to monitor activity in BYOD or public access networks, agent-based software is not realistic for tracking the user's personal activity (and in some states) Devices that do not provide a general picture of the user activity because they are illegal).

Even for agent-free software, a common mistake that many people make when implementing tools to monitor network traffic is that there are too many data sources at the beginning. There is no need to follow each network point. Instead, you must select the point where the data converges. Examples of this are the VLANs associated with the Internet gateways, the Ethernet ports of the WAN router, or the critical servers.     

3.   Sometimes real-time data is not enough

The ability to monitor network traffic in real-time is sufficient to achieve the objectives of network traffic monitoring, but real-time data may not be enough. Historical traffic metadata is ideal for forensic network analysis and is equally essential when analyzing past events, identifying trends, and comparing current network activity with the previous week. For these purposes, it is better to use a tool to monitor network traffic with a detailed packet inspection.

Some tools that monitor network traffic choose data aging. This means that the detail goes back as it goes back in history. This saves disk space but is not an ideal solution if you are trying to determine how an intruder has managed to defend against planting malware on your network. You can continue to search for non-existent answers without the exact and complete data associated with the event.

4.  Assistant the data with usernames

Traditional network traffic monitoring tools generally report activity using IP or MAC addresses. This is useful information, but it can be a problem in a DHCP environment if you are trying to find a problematic device. One piece of information that can link network activity to a device is the username. The username association tells you who is doing what on the network.

5.   Check the movements and packet payloads for apprehensive content

Many networks have intrusion detection systems on edge, but few networks have this type of technology to monitor internal traffic. Only a fake mobile or IoT device is needed to compromise the network. Another problem that I often see is a firewall that allows the passage of suspicious traffic where the rules are poorly configured.

The following image shows an example. Someone created a rule that allows incoming traffic on TCP 5901 (VLC remote desktop sharing) but did not limit it to a source and destination. The home address, in this case, seems to be registered in China, and connections from this country are not expected to connect to this network.