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strong authentication and secure communications over insecure channels. It is a replacement for rlogin, rsh, rcp,
and rdist.
SSH protects a network from attacks such as IP spoofing, IP source routing, and DNS spoofing. An attacker who
has managed to take over a network can only force ssh to disconnect. He or she cannot play back the traffic or
hijack the connection when encryption is enabled.
When using ssh's login (instead of rlogin) the entire login session, including transmission of password, is encrypted;
therefore it is almost impossible for an outsider to collect passwords.
SSH is available for Windows, Unix, Macintosh, and OS/2, and it also works with RSA authentication.
SSL
Secure Sockets Layer. Commonly used encryption scheme used by many online retail and banking sites to protect
the financial integrity of transactions. When an SSL session begins, the server sends its public key to the browser.
The browser then sends a randomly generated secret key back to the server in order to have a secret key exchange
for that session.
Static IP Address
A fixed address assigned to a computer or device that is connected to a network.
Subnet Mask
An address code that determines the size of the network.
Subnetwork or Subnet
Found in larger networks, these smaller networks are used to simplify addressing between numerous computers.
Subnets connect to the central network through a router, hub or gateway. Each individual wireless LAN will probably
use the same subnet for all the local computers it talks to.
Switch
A type of hub that efficiently controls the way multiple devices use the same network so that each can operate at
optimal performance. A switch acts as a networks traffic cop: rather than transmitting all the packets it receives to all
ports as a hub does, a switch transmits packets to only the receiving port.
TCP
A protocol used along with the Internet Protocol (IP) to send data in the form of individual units (called packets)
between computers over the Internet. While IP takes care of handling the actual delivery of the data, TCP takes care
of keeping track of the packets that a message is divided into for efficient routing through the Internet. For example,
when a web page is downloaded from a web server, the TCP program layer in that server divides the file into
packets, numbers the packets, and then forwards them individually to the IP program layer. Although each packet
has the same destination IP address, it may get routed differently through the network. At the other end, TCP
reassembles the individual packets and waits until they have all arrived to forward them as a single file.
TCP/IP
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