What does the network scanning mean? Network scanning refers to do with acomputer network to collect all information about computing systems. Networkscanning is basically used for security assessment and system maintenance.Hacker also uses network scanning for attacks.
Vulnerability scanning is one ofthe network scanning. Vulnerability scanning works for identifiesvulnerabilities of a computer system. It also can detect weak port and launchexploit.
Now I want to introduce a port scanning tool about Network Mapped(Nmap). It’ free of charge to use and open source utility. Nmap can run on atmany platforms, it runs on all operating system (OS), such as Window, Solaris,IRX, etc.Now I would list somefeatures and function about Nmap. One of the features is host discovery, it canattempt to determine the accessible host on the network. We can identify thenumber the hosts even ruleset of the firewall is written explicitly.
Nmap also canbe used to scan millions of IPs in a singlerun with incredible efficiency. We just need to be careful to understandand adjust the variables that can affect performance, and really think aboutour scan objectives beforehand.Mostof the security tools have advantage and disadvantage. Nmap has a lot ofadvantage, one of the advantages is that send a well-crafted packet to thedestination. Nmap also can scan the network for various vulnerabilities. It was actually designed to frequently scanlarge networks, still works fine in opposition to single hosts. Nmap also able to integrate with Zenmap GUI to create visual network maps andstore information on particular machines in a network. Can’t think of any moredisadvantages specific to Nmap, but port-scanning has some general flaws.
Oneof the disadvantages is hile Nmap is scanning weaker devices and congestednetworks can sometimes cause an unintentional DOS or network slowdown. This canbe remedied by slowing down the scan speed. Port scans are loud. There are waysto make port scans more stealthy included with Nmap, but they always requiregenerating a whole lot of network traffic, and there is an inverse relationshipbetween stealth and speed.Now I’d show some usage of Nmap.
I’lluse Nmap to ping scan the network, listing machines that respond to ping withthis command “nmap –sP Ip range”.I can open a Nmap front end calledZenmap with this command “nmapfe”. It is a GUI built on top of Nmap. The reasonI use Zenmap is that it provides a nice summarized output of Nmap commands andsupports all of the features Nmap does.I also can view all theactive host on the network with this command “nmap –v3 Ip range”.
I can scan 2 or moretype of scan in a command. Below are OS detection and UDP scanning with thiscommand “nmap –sS –O IP range”.There’s have othertools for network scanning in the field of network security. One of the toolscalled Nessus, let’s compare it with the Nmap. NMAP and Nessus can both be considered network securityscanners, but there are several difference between them. The first of which arethe ways information is presented to the user. Nmap whether you use the GUI orcommand line the data output is still text-based as where Nessus has more of agraphical approach to presenting the information.
At a basic level, Nessus is avulnerability scanner whereas NMAP is used for mapping a network’s hosts andthe hosts’ open ports. Nessus’ primary function is to provide security scanningcapabilities to its user. Like Nmap, it can do network discovery, but unlikeNmap, it is designed to scan systems to determine their vulnerabilities. Becauseof what Nessus can do, it can be applied in security audits, asset profiling, andvulnerability analysis.
All these can probably do with Nmap, but it would takea lot of work. Depending on your position and purpose, it may already be clearwhich tool is for you. However, if your main focus is making sure anyvulnerabilities are discovered, without the need to hire a network and securityexpert, then Nessus may just be the answer. If you are a penetration securityengineer and assigned to check out a company’s network, Nmap may just do thejob because of its portability and utility.