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DHCP (Dynamic Host Configuration Protocol) DHCP is a network protocol that is used to assign various network parameters to a device. This greatly simplifies administration, since there is no need to assign static network parameters for each device separately. DHCP is a client-server protocol. A client is a device that is configured to use DHCP to request network parameters from a DHCP server. DHCP server maintains a pool of available IP addresses and assignes one of them to the host. A DHCP server can also provide some other parameters, such as: • subnet mask • default gateway • domain name • DNS server Cisco routers can be used as a DHCP server. DHCP process explained: DHCP client goes through the four step process:   1: A DHCP client sends a broadcast packet (DHCP Discover) to discover DHCP servers on the LAN segment. 2: The DHCP servers receive the DHCP Discover packet and respond with DHCP Offer packets, offering ...

ARP (Address Resolution Protocol) is a network protocol used to find out the hardware (MAC) address of a device from an IP address. It is used when a device wants to communicate with some other device on a local network (for example on an Ethernet network that requires physical addresses to be known before sending packets). The sending device uses ARP to translate IP addresses to MAC addresses. The device sends an ARP request message containing the IP address of the receiving device. All devices on a local network segment see the message, but only the device that has that IP address responds with the ARP reply message containing its MAC address. The sending device now has enough information to send the packet to the receiving device. ARP request packets are sent to the broadcast addresses (FF:FF:FF:FF:FF:FF for the Ethernet broadcasts and 255.255.255.255 for the IP broadcast). ARP broadcast explained:  Let’s say that Host A wants to communicate with host ...