 and check if it contains its own IP address. Introduction to Telecommunications Network Engineering Hosts in subnet 1 are set to use default router 221.109.65.65 2) Subnet mask gives 221.109.65.64 and 5) "It is my address," 3) ARP request, ARP request is sent to port 1. ARP response including MAC broadcast: MAC (and IP) address "Who owns 1) IP packet with address 221.109.65.105 IP address 221.109.65.71 is received 221.109.65.71 221.109.65.71" by the router of network Subnetwork 1, 221.109.65.0 221.109.65.64, host addresses 221.109.65.65 4) "Not mine" 221.109.65.126 Port 1, 221.109.65.65 Port 2 221.109.65.101 221.109.65.129 Subnetwork 2, 221.109.65.128, host addresses 221.109.65.129 Hosts in subnet 2 are set to use default 221.109.65.190 router 221.109.65.129 221.109.65.130 Figure 6.44 Operation of ARP. The host having the IP address given in the ARP request frame responses with an ARP response frame containing its MAC and IP addresses. All hosts in the network may update their ARP caches by detecting ARP response frames and storing them for a few minutes. If one host in network 1 wants to transmit a packet to an IP address, it checks with the subnet mask see if the destination belongs to my own network. If this is the case it uses ARP to find out the destination MAC address. If the IP address does not belong to the same network, a packet is sent to the default router (usually the first address of the subnet). The IP address of the default router, subnet mask, and own IP address are configured to all hosts. Sometimes, for example in the case of diskless workstations, we might need to find out an IP address when the MAC address is known. The Reverse Address Resolution Protocol solves this problem. A newly booted worksta- tion sends an Ethernet frame, where type field is hex. The 8035 (32,821 decimal) and destination address is the broadcast address. It actually asks: "My Ethernet address is given here; does anybody know my IP address?" The RARP server that takes care of IP addresses for diskless workstations respo