In order to communicate or transfer the data from one computer to another computer we need some address. In Computer Network various types of address are introduced; each works at different layer. Media Access Control Address is a physical address which works at Data Link Layer. In this article, we will discuss about addressing in DLL, which is MAC Address.
Mac for Linux Geeks will assist you step by step in migrating from Linux based systems to OS X. Dual booting, virtualization, and building out the Linux environment on OS X are discussed in detail, along with a comparative view of well known Mac tools and their open source equivalents. The /dev Directory The /dev directory contains files that represent devices attached to the system, including physical devices, such as serial ports, and pseudodevices, such as a random number generator. Selection from Mac OS X for Unix Geeks Book.
Media Access Control (MAC) Address –
MAC Addresses are unique 48-bits hardware number of a computer, which is embedded into network card (known as Network Interface Card) during the time of manufacturing. MAC Address is also known as Physical Address of a network device. In IEEE 802 standard, Data Link Layer is divided into two sublayers –
The book wraps up with a quick manpage-style reference to the 'Missing Manual Pages'-commands that come with Mac OS X although there are no manpages.If you find yourself disoriented by the new Mac environment, Mac OS X for Unix Geeks can help you acclimate yourself quickly to the familiar, yet foreign, Unix. Oct 21, 2019 Unix was created fifty years ago at Bell Labs, a research and development company owned by AT&T. Fast-forward to 1973 and Version 4 of Unix, which was rewritten in the C programming language. This made the operating system much more portable and easier to transfer to different hardware platforms.
Logical Link Control(LLC) Sublayer
Media Access Control(MAC) Sublayer
MAC address is used by Media Access Control (MAC) sublayer of placeholder='Add your personal notes here! (max 5000 chars)'>
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Nmap is Linux command-line tool for network exploration and security auditing. This tool is generally used by hackers and cybersecurity enthusiasts and even by network and system administrators. It is used for the following purposes:
Real time information of a network
Detailed information of all the IPs activated on your network
Number of ports open in a network
Provide the list of live hosts
Port, OS and Host scaning
Installing Nmap Command
In case of Debian/Ubuntu
In case of CentOS/RedHat
Working with Nmap Command
1. To scan a System with Hostname and IP address. First, Scan using Hostname
Now let’s Scan using IP Address
The nmap command allows scanning a system in various ways. In this we are performing a scan using the hostname as “geeksforgeeks” and IP address “172.217.27.174”, to find all open ports, services, and MAC addresses on the system.
2. To scan using “-v” option.
It is used to get more detailed information about remote machine.
3. To scan multile hosts
We can scan multiple hosts by writing IP addresses or hostnames with nmap.
4. To scan whole subnet
We can scan a whole subnet or IP range with nmap by providing “*” with it. It will scan a whole subnet and give the information about those hosts which are Up in the Network.
5. To scan to detect firewall settings.
Detecting firewall settings can be useful during penetration testing and vulnerability scans. To detect it we use “-sA” option. This will provide you with information about firewall being active on the host. It uses an ACK scan to receive the information.
6. To identify Hostnames
We use “sL” option to find hostnames for the given host by completing a DNS query for each one. In addition to this “-n” command can be used to skip DNS resolution, while the “-R” command can be used to always resolve DNS.
7. To scan from a file
If we have a long list of addresses that we need to scan, we can directly import a file through the command line. It will produce a scan for the given IP addresses.
We use the “-h” option if we have any questions about nmap or any of the given commands. It shows the help section for nmap command, including giving information regarding the available flags.
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