Network experts need a tool called a scanner to assess the state of the network and ensure that packets are transmitted properly over the network. 

A scanner, which in Persian means scanner, is a computer program or piece of hardware that can intercept and record the flow of information in a network or part of a network.

The scanner monitors the flow of packets being exchanged across the network and, if necessary, decodes the raw information of the packets, displays the information of the various parts of the packet, and analyzes them according to its own map or other design specifications…

What is package recording?

Scanners are used to record packets on networks, but what is packet recording? Packet Capture is the act of recording data packets on a computer network.

Deep Packet Capture is the operation of recording a packet at high network speed, and recording packets of that network in full (header and body) on a network with a high traffic rate.

Once a packet has been recorded and stored, whether in short-term or long-term memory, then software tools perform deep packet inspection operations to review packet data, perform legal analysis to determine the root cause of network problems, identify security threats, and ensure communications compliance.

Enforce packages and network usage with specified policies. Some deep closed recording operations can be accompanied by in-depth inspection operations and as a result can manage, review and analyze all network traffic in real-time and at the same time maintain a historical archive of all network traffic for future analysis.

Partial packet recording can record packet headers without its data part.

This reduces the storage space required and prevents legal problems. However, it still has enough data to reveal the information needed to diagnose the problem.

What are the capabilities of scanners?

On wired network networks, depending on the network structure (switch), one can receive traffic on all or only parts of the network through a machine on the network. However, there are ways in which switches prevent network traffic from being accessed through other systems.

For network monitoring, it may be appropriate to monitor all data packets on a LAN using a network switch called a monitoring port. The purpose of the monitoring port is to reflect all packets passing through all switch ports when systems (computers) are connected to a switch port. For this purpose, a network tap is more suitable than using port monitoring.

Because taps are less likely to drop packets during high traffic. On wireless LANs, a person can capture traffic on a specific channel or multiple channels using multiple adapters.

On wired broadcast LANs and wireless LANs to record traffic, unicast traffic is sent to a machine running Sniffer software.

Multicast traffic is sent to a multicast group that a machine is listening to.

And for broadcast traffic, a network adapter is used, which must be placed in promiscuous mode to record traffic, which some snipers support and some do not.

On wireless LANs, even if the adapter is in promiscuous mode, packets will usually be ignored not for the service suite but for the adapter to be configured. The adapter must be monitored to see their packages.

The recorded digital data is decrypted into a human-readable format so that users of the protocol analyzer can easily revise the information exchanged.

Protocol analyzers modify their capabilities to display data in multiple views, automatically detect errors, determine root errors, generate timelines, recreate TCP and UDP data streams, etc. Some protocol analyzers also They can generate traffic and act as a reference.

These can act as protocol testers.

Testers generate the correct protocol traffic for the test and may also have the ability to detect test errors. Protocol analyzers can also be hardware-based, either in probe format, or more commonly combined with a disk array.

These devices record packets to the disk array. This allows packets to be analyzed without having to re-create any errors.

What are scanners used for?

Internal pointed out. One of the most important scanners used these days is TCP dumping.

How do scanners serve network experts?

Since scanners are used to record packets, they provide accurate information to network experts. Among the important services that scanners provide are the following:

Identify security vulnerabilities

Analysis of historical data recorded by Deep Closed Recording (DPC) helps determine the sources of unauthorized entry. The DPC can record the traffic that accesses specific servers and other systems to verify that the flow of traffic belongs to authorized employees. However, this technique can not work as an intrusion prevention system.

Data leak detection

Analysis of historical data by the DPC also helps to review the content and identify data leaks and determine its source. DPC data analysis can also reveal which files have been sent offline.

Network troubleshooting

If an adverse event is detected on the network, the cause or source can be more reliably identified if the network administrator has access to complete historical data. The DPC can record all packets continuously on important network connections.

When an event occurs, the network administrator can have accurate access to the circumstances surrounding it, take corrective action, and make sure that no more problems occur. This helps to reduce the average repair time.

Legal prevention

Packet recording can be used to fulfill an obligation issued by the LEA law enforcement agency to provide all of the network traffic generated by the individual. Internet Service Providers (ISPs) and voice-over-Internet Protocol providers in some countries have to comply with the rules. The DPC records all network activity.

By recording and storing packets, telecommunications agents can provide the legally required security, separate access to target network traffic, and use a common device for internal network security purposes.

DPC detectors can record loss-free traffic without compromising network performance.

However, DPC devices may not be able to provide a document review chain, or satisfactory security for use in this application.

Diagnose data loss

If unauthorized entry causes information to be stolen (such as credit card numbers, social security numbers, medical information, etc.), the network administrator can determine exactly what information has been stolen and what information is still secure.

This can be useful for litigation when a credit card company receives a fraudulent request for an unauthorized purchase of the card.

Review security solutions

Once the unauthorized extraction or entry is detected by the DPC, the system administrator may respond to the attack on the system to prevent it. This helps the manager know if his solution has worked.

Legal issues

Closed recordings for forensic investigations can also be easily done using open-source tools and systems. Examples of these tools are Free BSD and dumpcap.

Comparative performance

If performance drops suddenly, historical data can allow the administrator to view a specific time window and identify the cause of performance issues.