Networking with the TCP/IP Protocol Suite

Homeworks

Lap Leung

International Organization for Standardization (ISO) established the Open Systems Interconnection (OSI) communication standards. It has 7 layers: physical, data-link, network, transport, session, presentation, and application.

Network Interface Card (NIC) connects a component to network. It ranslate signals between the network media and the component.

A transmition process used by Ethernet

It is used to translate network protocol addresses to MAC addresses.

It is used to translate network MAC addresses to protocol addresses.

It is a network interface using fiber-optic devices.

It resolves IP names to IP addresses.

An organization of Electrical and Electronics Engineers.

The birth place of BSD Unix. It established some standards for TCP/IP.

It provides Internet services.

It is the protocol for Internet.

The maximum size of data that can be transfered.

The sponsor for Internet development. The root of DNS.

Pack bits into uniform size of cells, then transmit.

A group people who design and engineering the TCP/IP and Internet.

Documentation for computing and networking.

It uses TCP to transfer files.

It is used to measure the speed of network traffic.

It is used on Thicknet.

It detects error.

Infomation relates to the topic.

Additional information of the topic.

7 layers: physical, data-link, network, transport, session, presentation, and application.

Layer 1 - Physical layer defines the cable or physical medium.
Layer 2 - Data Link layer defines the format of data on the network.
Layer 3 - Network layer defines network addresses.
Layer 4 - Transport layer subdivides user-buffer into network-buffer sized datagrams and enforces desired transmission control.
Layer 5 - Session protocol defines the format of the data sent over the connections.
Layer 6 - Presentation layer converts local representation of data to its canonical form and vice versa.
Layer 7 - Application layer provides network services to the end-users.

Layer 3 to layer 5

The Ethernet originated as a laboratory project at Xerox Corporation in 1974. It was developed as an inexpensive way of sending information quickly between office machines connected together in a single room or building, but it rapidly became a standard computer interconnection method. The data rate is 10 megabits per second. The original specification required coaxial cable as the communications medium, but costs have been reduced through the employment of simple paired wires.

A router is a internetworking device connecting networks.
A bridge is a LAN device connecting segments of a LAN.
A switch is a LAN device tranfering data from source to destination directly.
A Gateway is the interface of the networks.

A connection-oriented service establishes connection between the source and destination first, then trasmit data.
A connectionless service trasmits data from source to destination regardless the connectivity.

IP has 3 classes. They have different maximum number of networks and hosts. Numbe 0 and 255 cannot be used.
Telephone has only 1 class, Area Code. Under each area code, all number can be used and the maximum is 1,000,000.

IP address can be changed for the same IP name and you want to keep the infomation update.

I expect a high speed LAN to have a larger MTU than a wide area network. Because LAN has less packet loss than WAN. The larger MTU allows the larger packet. The larger packet takes more time to transmit and the packet loss can cost more time than smaller packet.

SNMP consists of a simply composed set of network communication specifications that cover all the basics of network management in a method that poses little stress on an existing network.

IPX is a proprietary standard developed by Novell derived from Xerox's Internet Datagram Protocol [6] (IDP).

RIP is an implementation of a distance-vector, or Bellman-Ford routing protocol for local networks.

It defines a Proposed Standard for an inter-autonomous system routing protocol for the Internet.

It is used in e-mail service.

WAIS is an electronic publishing software set which allows people to search out and retrieve different kinds of information from WAIS servers.

The XNS architecture defines five different levels or layers (0 through 4), which correspond closely to the OSI model.

SLIP and PPP define methods of sending Internet Protocol (IP) packets over standard EIA/TIA-232 asynchronous serial lines with minimum line speeds of 1200 baud.

"Routing" is to search a path to connect source and destination.

getprotobyname(), sendto(), recvfrom(), connect()
read() or recv(), and write() or send()

This program attempts to trace the route an IP packet would follow to some internet host by launching UDP probe packets with a small ttl (time to live) then listening for an ICMP "time exceeded" reply from a gate- way. We start our probes with a ttl of one and increase by one until we get an ICMP "port unreachable" (which means we got to "host") or hit a max (which defaults to 30 hops and can be changed with the -m flag). Three probes (which can be changed with the -q flag) are sent at each ttl setting and a line is printed showing the ttl, address of the gate- way and round trip time of each probe. If the probe answers come from different gateways, the address of each responding system will be printed. If there is no response within a 3 second timeout interval (which can be changed with the -w flag), a "*" is printed for that probe.
Traceroute show the path, but Ping does not .

IP address has 16 bytes, which contains the infomation of the IP subnet and host. Each TCP/IP network has a subnet mask, which identifies the subnet of the IP address and the host of that subnet. When a IP packet arrived at the gateway the destination IP address would be masked and compared with the subnet number. It they are the same, it would pass through the gateway. The hosts in the subnet would compare the host number and accept the matched packet.
The purpose of subnetting is to create more networks.
The address-depletion problem is lack of IP addresses.

.no - Norway
.se - Sewdian
.au - Austrilia
.us - USA
.nz - New Zealan
.ca - Canada
.nl - Netherland
.uk - United Kindom
.it - Italy
.sg - Singapore

.th - Thailand
.dk - Denmark

The primary purpose of the DNS is to resolve IP addresses dynamically.
Pro: It is dynamic. The same IP name can be moved to anywhere.
Con: It take a lot more time to find the host IP.
The alternative to participating in the DNS is to create a host file on the local host, map IP name to IP address.
Pro: Simple and fast.
Con: It is static; therefore, it is hard to update.

Bind - bind a name to a socket
Named - Internet name domain server daemon
DNS - Domain Name Server
WINS - Windows Internet Name Server
Host Table - /etc/hosts

named

president@whitehouse.gov

It is not proprietary. It is developed and supported by the Internet community.
It is a open protocol.

Because IP packets do not have to travel at the same path and arrive in the sequence.