Kerio Tech Firewall6 manual Glossary of terms, Proxy server, Routing table, Script, 390

Glossary of terms

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

Protocol inspector

WinRoute’s plug-in (partial program), which is able to monitor communication us- ing application protocols (e.g. HTTP, FTP, MMS, etc.). Protocol inspection is used to check proper syntax of corresponding protocols (mistakes might indicate an intru- sion attempt), to ensure its proper functionality while passing through the firewall (e.g. FTP in the active mode, when data connection to a client is established by a server) and to filter traffic by the corresponding protocol (e.g. limited access to Web pages classified by URLs, anti-virus check of downloaded objects, etc.).

Unless traffic rules are set to follow a different policy, each protocol inspector is automatically applied to all connections of the relevant protocol that are processed through WinRoute.

Proxy server

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.

Routing table

The information used by routers when making packet forwarding decisions. Pack- ets are routed according to the packet’s destination IP address. The routing table can be viewed in Windows operating systems using the route print command.

Script

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).

SMTP

Simple Mail Transfer Protocol is used for sending email between mail servers. The SMTP envelope identifies the sender/recipient of an email.

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