| A | B |
|---|
| TCP/IP enables communication among any | set of interconnected networks and is equally well suited for both LAN and WAN communication |
| The layers most closely affected by TCP/IP are | Layer 7 (application), Layer 4 (transport), and Layer 3 (network). |
| The function of the TCP/IP protocol stack, or suite, is | the transfer of information from one network device to another |
| The TCP/IP protocol stack application layer supports | file transfer, email, remote login, network management, and name management |
| DNS (Domain Name System) is a system used in the Internet for | translating names of domains and their publicly advertised network nodes into addresses |
| WINS (Windows Internet Naming Service) | a Microsoft-developed standard for Microsoft Windows NT that automatically associates NT workstations with Internet domain names |
| HOSTS | a file created by network administrators and maintained on servers. They are used to provide static mapping between IP addresses and computer names |
| POP3 (Post Office Protocol) | an Internet standard for storing e-mail on a mail server until you can access it and download it to your computer. It allows users to receive mail from their inboxes using various levels of security |
| SMTP (Simple Mail Transport Protocol) | governs the transmission of e-mail over computer networks. It does not provide support for transmission of data other than plain text |
| SNMP (Simple Network Management Protocol) | a protocol that provides a means to monitor and control network devices, and to manage configurations, statistics collection, performance and security |
| FTP (File Transfer Protocol) | a reliable connection-oriented service that uses TCP to transfer files between systems that support FTP. It supports bi-directional binary file and ASCII file transfers |
| TFTP (Trivial File Transfer Protocol) | a connectionless unreliable service that uses UDP to transfer files between systems |
| HTTP (Hypertext Transfer Protocol) | is the Internet standard that supports the exchange of information on the World Wide Web and supports many different file types, including text, graphic, sound, and video |
| Telnet | a standard terminal emulation protocol used by clients for the purpose of making remote terminal connections |
| PING (Packet Internet Groper) | a diagnostic utility used to determine whether a computer is properly connected to devices/Internet. |
| Traceroute | traces the path a packet takes to a destination, and is used to debug routing problems |
| Windows-based protocol: NBTSTAT | a utility used to troubleshoot NetBIOS name resolution; used to view and remove entries from the name cache |
| Windows-based protocol: NETSTAT | a utility that provides information about TCP/IP statistics; can be used to provide information about the status of TCP/IP connections and summaries of ICMP, TCP, and UDP. |
| Windows-based protocol: ipconfig/winipcfg | utilities used to view current network settings for all ip (nic) adapters on a device; can be used to view the MAC address, IP address, and gateway |
| The two transport layer protocols | TCP and UDP |
| TCP | a connection-oriented, reliable protocol; provides flow control by providing sliding windows, and reliability by providing sequence numbers and acknowledgments |
| The advantage of TCP | it provides guaranteed delivery of the segments |
| UDP | connectionless and unreliable; although responsible for transmitting messages, no software checking for segment delivery is provided at this layer |
| The advantage of UDP | speed |
| transport layer | flow control |
| TCP Layer 4 data stream | a logical connection between the endpoints of a network that provides transport services from a host to a destination |
| sequence number | the number used to ensure correct sequencing of the arriving data |
| acknowledgment number | the next expected TCP octet |
| UDP uses no | windowing or acknowledgments |
| Protocols that use UDP | TFTP, SNMP, DNS, NFS |
| Port numbers | used to keep track of the different conversations that cross the network at the same time |
| FTP port number | 21 |
| Telnet port number | 23 |
| DNS port number | 53 |
| Port numbers below 255 are | used for public applications |
| Port numbers above 1023 are | unregulated |
| Sequence numbers | used to track the order of packets and to ensure that no packets are lost in transmission |
| window size | specifies the number of bytes, starting with the acknowledgment number, that the receiving host's TCP layer is currently prepared to receive |
| The purpose of windowing | to improve flow control and reliability |
| sliding window | the window size is negotiated dynamically during the TCP session |
| If at the receiving station a sequence number is missing in the series | that segment is retransmitted |
| If segments are not acknowledged within a given time period | retransmission occurs |
| TCP/IP Internet layer protocols | IP, ICMP, ARP, RARP |
| IP | provides connectionless, best-effort delivery routing of datagrams |
| ICMP | provides control and messaging capabilities |
| ARP | determines the data link layer address for known IP addresses |
| RARP | determines network addresses when data link layer addresses are known |
| The protocol field determines | the Layer 4 protocol being carried within an IP datagram |
| ICMP messages are carried in IP datagrams and are used to | send error and control messages |
| If a router receives a packet that it is unable to deliver to its final destination, the router | sends an ICMP unreachable message to the source |
| If the destination address is not in the ARP table, ARP sends | a broadcast that will be received by every station on the network, looking for the destination station. |
| The transport layer performs two functions: | Flow control, which is provided by sliding windows and reliability, which is provided by sequence numbers and acknowledgments |
| RARP relies on the presence of a | RARP server with a table entry or other means to respond to RARP requests |
