• Does TCP/IP encompass a single protocol or multiple?
• If multiple protocols make up TCP/IP, discuss some of them and how they fit within the OSI Model.
• You need to permit clients with laptops access to the Internet. As such you need to configure your network DHCP server to issue them IP addresses automatically. What DHCP option should you put into place to allow for this? Is there more than one way to perform this action?
TCP/IP encompasses multiple protocols: The TCP/IP protocol component that is installed in your network operating system is a series of interconnected protocols called the core protocols of TCP/IP. All other applications and other protocols in the TCP/IP protocol suite rely on the basic services provided by the following protocols: IP, ARP, ICMP, IGMP, TCP, and UDP.
1. IP: It is a connection-less, unreliable data gram protocol primarily responsible for addressing and routing packets between hosts. Connectionless means that a session is not established before exchanging data. Unreliable means that delivery is not guaranteed. IP always makes a “best effort” attempt to deliver a packet. An IP packet might be lost, delivered out of sequence, duplicated, or delayed. IP does not attempt to recover from these types of errors. The acknowledgment of packets delivered and the recovery of lost packets is the responsibility of a higher-layer protocol, such as TCP. IP is defined in RFC 791.
When IP packets are sent on shared access, broadcast-based networking media — such as Ethernet or Token Ring — the media access control (MAC) address corresponding to a forwarding IP address must be resolved. ARP uses MAC-level broadcasts to resolve a known forwarding or next-hop IP address to its MAC address. ARP is defined in RFC 826.
Internet Control Message Protocol (ICMP) provides troubleshooting facilities and error reporting for packets that are undeliverable. For example, if IP is unable to deliver a packet to the destination host, ICMP sends a Destination Unreachable message to the source host. The following table shows the most common ICMP messages.