This Microsoft's proprietary technology is used for creation of dynamic objects for web pages. This technology provides many features, such as writing to disk or execution of commands at the client (i.e. on the host where the Web page is opened). This technology provides a wide range of features, such as saving to disk and running commands at the client (i.e. at the computer where the Web page is opened). Using ActiveX, virus and worms can for example modify telephone number of the dial-up.
ActiveX is supported only by Internet Explorer in Microsoft Windows operating systems.
A virtual bidirectional communication channel between two hosts.
See Also TCP.
Software or hardware device that protects a computer or computer network against attacks from external sources (typically from the Internet).
In this guide, the word firewall represents the WinRoute host.
File Transfer Protocol.
Internet Message Access Protocol (IMAP) enables clients to manage messages stored on a mail server without downloading them to a local computer. This architecture allows the user to access his/her mail from multiple locations (messages downloaded to a local host disk would not be available from other locations).
IP address is a unique 32-bit number used to identify the host in the Internet. It is specified by numbers of the decimal system (0-255
) separated by dots (e.g. 195.129.33.1
).
The equipment that connects hosts to a traffic medium. It can be represented by an Ethernet adapter, TokenRing adapter, by a modem, etc. Network adapters are used by hosts to send and receive packets. They are also referred to throughout this document as a network interface.
Peer-to-Peer (P2P) networks are world-wide distributed systems, where each node can represent both a client and a server. These networks are used for sharing of big volumes of data (this sharing is mostly illegal). DirectConnect and Kazaa are the most popular ones.
Post Office Protocol is an email accessing protocol that allows users to download messages from a server to a local disk. It is suitable for clients who don't have a permanent connection to the Internet.
16-bit number (1-65535
) used by TCP and UDP for application (services) identification on a given computer. More than one application can be run at a host simultaneously (e.g. WWW server, mail client, FTP client, etc.). Each application is identified by a port number. Ports 1-1023
are reserved and used by well known services (e.g. 80
= WWW). Ports above 1023
can be freely used by any application.
Microsoft's proprietary protocol used for design of virtual private networks.
See Also VPN.
Local networks which do not belong to the Internet (private networks) use reserved ranges of IP addresses (private addresses). These addresses cannot be used in the Internet. This implies that IP ranges for local networks cannot collide with IP addresses used in the Internet.
The following IP ranges are reserved for private networks:
10.0.0.0/255.0.0.0
172.16.0.0/255.240.0.0
192.168.0.0/255.255.0.0
Older, but still wide-spread method of Internet connection sharing. Proxy servers connect clients and destination servers.
A proxy server works as an application and it is adapted for several particular application protocols (i.e. HTTP, FTP, Gopher, etc.). It requires also support in the corresponding client application (e.g. web browser). Compared to NAT, the range of featured offered is not so wide.
A computer or device with one or more network interfaces between which it handles packets by following specific rules (so called routes). The router's goal is to forward packets only to the destination network, i.e. to the network which will use another router which would handle it on. This saves other networks from being overloaded by packets targeting another network.
See Also Routing table.
The information used by routers when making packet forwarding decisions (so called routes). Packets are routed according to the packet's destination IP address. On Windows, routing table can be printed by the route print
command, while on Unix systems (Linux, Mac OS X, etc.) by the route
command.
A code that is run on the Web page by a client (Web browser). Scripts are used for generating of dynamic elements on Web pages. However, they can be misused for ads, exploiting of user information, etc. Modern Web browsers usually support several script languages, such as JavaScript and Visual Basic Script (VBScript).
Simple Mail Transfer Protocol is used for sending email between mail servers. The SMTP envelope identifies the sender/recipient of an email.
Undesirable email message, usually containing advertisements.
Spoofing means using false IP addresses in packets. This method is used by attackers to make recipients assume that the packet is coming from a trustworthy IP address.
SSL is a protocol used to secure and encrypt network communication. SSL was originally designed in order to guarantee secure transfer of Web pages over HTTP protocol. Nowadays, it is used by almost all standard Internet protocols (SMTP, POP3, IMAP, LDAP, etc.).
At the beginning of communication, an encryption key is requested and transferred using asymmetrical encryption. This key is then used to encrypt (symmetrically) the data.
Transmission Control Protocol is a transmission protocol which ensures reliable and sequential data delivery. It is used by most of applications protocols which require reliable transmission of all data, such as HTTP, FTP, SMTP, IMAP, etc.
Name used for all traffic protocols used in the Internet (i.e. for IP, ICMP, TCP, UDP, etc.). TCP/IP does not stand for any particular protocol!
User Datagram Protocol is a transmission protocol which transfers data through individual messages (so called datagrams). It does not establish new connections nor it provides reliable and sequential data delivery, nor it enables error correction or data stream control. It is used for transfer of small-sized data (i.e. DNS queries) or for transmissions where speed is preferred from reliability (i.e. realtime audio and video files transmission).
Virtual Private Network, VPN represents secure interconnection of private networks (i.e. of individual offices of an organization) via the Internet. Traffic between both networks (so called tunnel) is encrypted. This protects networks from tapping. VPN incorporates special tunneling protocols, such as Microsoft's IPSec and PPTP (Point-to-Point Tunnelling Protocol).
WinRoute contains a proprietary VPN implementation called Kerio VPN.