Network Packet Sniffing Tools — A Complete Guide
There are legitimate uses of packet sniffers, including monitoring employee network usage and safeguarding users against harmful files, conversations, and activities. A packet sniffer has several advantages such as improving network traffic, improving bandwidth efficiency, and many more. Network packet sniffing tools are used to identify the right protocol used for communication. These tools are helpful in finding the right evidence to prove a patent infringement, and these evidences can be used in a patent infringement claim chart. To know more, how patent infringement claim charts are made, contact us.
What are Network Packets?
Every network comprises numerous elements, including workstations, servers, networking devices, and more. All of these elements are referred to as nodes in the context of networking. A stable network connection makes sure that data is sent between these nodes consistently and at a reasonable speed based on the capacity of the network. Modern networks include a combination of physical and wireless connectivity. Although, these networks use the same basic concepts for transmission of data. Data is exchanged among different nodes in a network in the form of compact data chunks known as packets. Depending on the network protocol, these packets have different formats. Along with actual data, the packets include control information to facilitate the transport of packets from transmitter to the receiver. As packets intended to be sent to a particular node frequently transit through several nodes in a network and have the possibility to reach at the inaccurate node, the control information is necessary. To make sure that packets arrive at their intended location, the control information comprises the IP (Internet Protocol) addresses of the source and the destination, packet sequencing information (such as packet number), and more.
What are Network Packet Sniffers and Why do we Need Them?
There is no defined way to retrieve the packets lost during communication in protocols like Transmission Control Protocol/Internet Protocol (TCP/IP). Network designers employ these protocols only in fault-tolerant networks, where communication is unaffected by losses that fall below predetermined limits. In contrast, in protocols like User Datagram Protocol (UDP), the sender keeps sending the packet until it gets the recipient’s acknowledgement. While improving transmission performance, it also uses more resources. It can cause considerable delays in net transmission rates if left unchecked. Packet sniffers provide a solution to resolve such issues.
Using packet sniffers, data flow is intercepted as it travels across the network and copied to a file. Data packets sent over a network go through a number of nodes. A packet’s control information is examined by each network device to determine the destination node. In most cases, a node ignores a packet that it discovers is directed to another node. In contrast, the nodes designed for packet sniffing deviate from this standard approach and gather all or a specified sample of packets, regardless of their destination address. The process is called Packet Sniffing. These packets are used by packet sniffers to analyse networks. Network managers employ packet sniffing tools to track and verify network traffic whereas hackers might use them for illicit activities. Sniffers can be set up in two different ways. The first is “unfiltered,” which means it will record every packet it can and save it for subsequent analysis. The next mode is “filtered,” in which analysers only record packets that include a given set of data items. Both wired and wireless networks can utilise packet sniffers, but the effectiveness of their usage relies on how much of the network they are capable to observe because of network security measures. Sniffers may have access to all packets on a wired network or may be constrained by the location of network switches. Most sniffers could only monitor one channel at a moment on a wireless network, however using several wireless interfaces can increase these capabilities.
Types of Network Packet Sniffers
1. Hardware Packet Sniffers: It is a hardware element that is inserted into a network in order to do packet sniffing. Network administrators frequently employ hardware packet sniffers to examine a specific area of a vast network. These packet sniffers are employed by the network managers to assure that all packets are collected without any loss due to routing, filtering, or any other network concern. The hardware packet sniffers may be configured to transmit all packets it has collected to a central location for additional analysis.
2. Software Packet Sniffers: Software packet sniffers are more commonly employed by most enterprises. Every computer or node has a Network Interface Card to connect to the network, which is often set up to ignore packets that are not routed to it. A Software Packet Sniffer modifies this behaviour, allowing for the monitoring of all network traffic. The amount of data that is gathered by this type of packet sniffer depends upon whether the packet sniffer is in filtered or unfiltered mode.
Advantages of Network Packet Sniffers
There are legitimate uses of packet sniffers, including monitoring employee network usage and safeguarding users against harmful files, conversations, and activities. A packet sniffer has several advantages such as improving network traffic, improving bandwidth efficiency, and many more, some of which are discussed below.
1. Identifying root cause of a network issue: It might be challenging to pinpoint which network or application component is the cause for a slowdown or any other issue. Network administrators can easily pinpoint the elements causing delay, or packet loss by collecting data from all points of their network using packet sniffers.
2. Network Traffic Management: Understanding the network’s traffic is crucial for analysing network. Traffic may be divided into several categories using the appropriate packet sniffers based on the IP addresses of the destination servers, the ports being utilised, and measurements of the total and relative amounts of traffic for each type.
3. Bandwidth Efficiency Improvement: Network administrator may simply discover the traffic flow and WAN bandwidth use, any unusual increases in network usage, and more with traffic analysis using network sniffers. With this information, businesses may prioritise bandwidth allotment for critical apps.
4. Network Security Improvement: A high amount of outgoing traffic could be a sign that a hacker is utilising your applications to communicate with the outside world or move a lot of data. A packet sniffer can identify odd traffic spikes and a network administrator can investigate further to see if a cybercriminal is active.
5. Using Network Packet Sniffing Tools for Communication Specifications
Packet sniffing tools can be used to get information about protocols, source, destination, and other data related to packets sent from one node to the other. For illustration, packet sniffing process using Wireshark is discussed briefly. Wireshark captures the packet and arranges the collected packets in a descriptive packet list. Wireshark provides information about source, destination, network protocols, and length of the packet etc. To get detailed information about a packet, one can click on a particular packet in the list. For data display, Wireshark employs a color-coding scheme. Each packet is labelled with a distinct colour to signify the various types of traffic.
Use Case — Wireshark
- The time column in Wireshark gives a time stamp for a packet that reflects the time after which the packet is received when packet sniffing begins. For example, in packet number 39 in figure 2, the time 3.832609 represents that the 39th packet is received after 3.832609 seconds from the beginning of packet sniffing.
- The ‘Source’ and ‘Destination’ columns include source and destination identifying data. This data might be in the form of an IP address, a Media Access Control (MAC) address, or any other identification-based information. For example, in 39th packet, 192.168.2.1 and 192.168.2.130 represents the IP address of the source and destination respectively. Similarly, in 38th packet, a2:85:2a:14:5f:d2 represents the MAC address of the source and ‘Broadcast’ in the destination column represents that the message is being broadcasted to the network devices by the source.
- The ‘Protocol’ column contains information about the network protocol utilised for communication. For example, in 39th packet, Address Resolution Protocol (ARP) protocol is mentioned which is used to map an IP address to the MAC address of the device that has that IP address. In this case, Wireshark provides MAC address of the source device which is inquiring about the device in the network having a specific IP address. In 38th packet, Domain Name System (DNS) protocol is mentioned which is used to send a DNS query to a name server to resolve a domain. For example, when any website is searched in the web browser, it triggers a DNS request, which is sent by the computer to a DNS server in order to get the website’s IP address.
- Wireshark also provides the packet length in bits in the ‘Length’ section and the details about the packet in the ‘Info’ section. For example, in 39th packet, 42 in the Length column represents that the packet size is 42 bits and ‘Who has 192.168.2.1?’ in the Info section represents that the source is enquiring about the device in the network whose IP address is 192.168.2.1.
Comparing Top Network Packet Sniffers
Packet sniffing tools, as well as some of the most popular packet sniffers used by network administrators all over the world, have been thoroughly discussed. As described in the case of Wireshark, packet sniffers give critical information about packets such as network protocols used for transmission, source and destination identification, packet length, and other data related to the packets that are transferred from one node to another in a network. Network Packet Sniffers may be installed on all major platforms and provide useful features such as network infrastructure monitoring, bandwidth monitoring, efficiency improvement, and security enhancement.
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