=== Part 3: Network Connectivity & Network Service Troubleshooting Utilities===
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|{{Admon/note | Obtaining Remote MAC Addresses| The term '''MAC''' address stands for '''Media Access Control''' address, which provides a unique ID to prevent confusion among computer systems within a network. While we use '''32bit IP addresse'''s to communicate over an internet, on the local ethernet network packets are delivered to a '''48bit hardware address''' (sometimes called a MAC address). The '''ARP''' protocol resolves 32bit IP addresses to 48bit MAC addresses by using a broadcast and caching the results. We can examine the ARP cache to get the MAC addresses of other computers to solve problems involving MAC addresses (such as '''Wake Up on Lan''').}}
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Troubleshooting network problems is an extremely important and frequent task that a Linux/Unix system administrator performs on a daily basis! Since network services (such as file-server, print-servers, web-servers, and email-servers) depend on network connectivity, as Linux/Unix sysadmin must be able to quickly and effectively pin-point sources of network problems in order to resolve them.