World's most popular travel blog for travel bloggers.
Showing posts with label Networking. Show all posts
Showing posts with label Networking. Show all posts
(1)cAT[OPTIONS] FILE  -  concatenate (list) a file

(2) diff [option] file1 file2  - compare the two files and display the differnces (text files only)

(3) sort [option] file  -  read commands form the file and execute them in the current shell. source: C shell, :Bpurne charc


(4)cmp[option] file1 file2  -  compress file and save it as file.Z

(1) DNS architecture

Name SERVERS are server programs, which hold information about the domain tree's structure and set information. A name server may cache structure or set information about any part of the domain tree, but in general a particular name name server has complete information about a subset of the domain space and pointers to other name servers that can be used to lead to information from any part of the domain tree

(2) DNS Zones


The zone, as indicated in the figure on the next page, is a subtree of the DNS that is administered separately. A name server can support multiple zones. Zones are contiguous regions of the name space, where each can be forked into sub zones. Each of these sub zones can have its independent management.
A network topology refers to the physical layout of the network in which all the devices are connected. This includes all the hardware that makes up the network. The points of connection to the network by the stations are called nodes or workstations.A number of possible network topologies are available. The choice of network topology for installing a computer network depends upon a combination of following factors:
·         Desired performeace of the system
·         Desired reliability of the entire system
·         Size of the system
·         Expendability of the system
·         cost of the components and services required to implement the network
·         Availability of communication lines.

1. linear bus

  A linear bus topology consists of a main run of cable with a terminator at each end. All nodes are connected to the linear cable

2.Star

A star topology is designed with each node connected directly to a central network hub or conceentrator. Data on a star network passes through the hub or concentrator before continuing to its destination. The hub or concentrator manages and controls all function of the network . It also acts as a repeater for the data flow.

3. star wired ring

A star wired ring topology my appear to be the same as a star topology. Internally, the MAU( multistation acces unit) of a star wired ring contains wiring that allows information to pass from one device to another in a circle or ring.

4. Mesh topology


In a mesh topology, each computer on network has redundant data paths. The mesh topology  provides fault tolerance if a wire, hub , switch, or other component fails, data can travel along an alternate path. A digram of a mesh network looks like a fishing net.