Remote Authentication Dial-In user Service. A standard for authentication and accounting, RADIUS is primarily used to control dial-up access to PPP and other services. The protocal was standardized in RFC 2058, the current implementation is defined in RFCs 2138 and 2139. RADIUS uses UDP packets, older servers use ports 1645 and 1646, the current standard is port 1812 for authentication and 1813 for accounting.
See also TACACS.
Acronym for Random Access Memory, a form of primary storage that allows direct read and write operations. RAM storage is generally a very high-speed medium that requires constant power to avoid data loss.
See also ROM. (rezidew)
Reverse ARP, a mechanism to match a MAC address to the corresponding IP address.
Remote Access Server. Generally used to refer to NT services, RAS is similar to NAS both terms describe specialized models of terminal server
Realtime Blackhole List. A list of open mail relays and rogue sites, maintained by Paul Vixie. Subscribers to the RBL reject all mail and/or connection attempts from RBL'd IP addresses, effectively cutting off irresponsible/incompetent domains from the rest of the Internet. Subscription is completely voluntary, details are at http://maps.vix.com/rbl/.
Regular Expression.
Regular Expressions use Meta Characters to express variable parts of a pattern to be matched. Regular Expression. (rezidew)
Acronym for Request For Comment, these a broad range of notes covering a variety of topics related to the Internet. RFCs are handled by the IETF and are archived at several sites.
Router Information Protocol, a standard mechanism for exchanging routes (paths) between routers, this protocol is slowly being replaced by OSPF. RIP is specified in RFC 1058.
Reduced Instruction Set Computer. A CPU based on a limited number of basic instructions, systems using RISC result in larger binary files but overally faster execution of each instruction.
The Unix command. to delete a file from a directory.
The Unix command. to delete a directory.
Acronym for Read-Only Memory, ROM is used for permanent storage, such as system bootstrap routines.
See also RAM. (rezidew)
1: The 'base' or bottom of a system. e.g. the 'root directory' is the lowest possible directory in a filesystem, and in X11 the 'root window' is the background on which all other windows are drawn. 2: In Unix, the user 'root' is the user that owns the system and has full superuser power.
A simple form of encryption in which the letters A-M are transposed with the letters L-Z, often used in Usenet postings of offensive jokes to prevent people from accidentally reading a disturbing message.
Shorthand for Rolling On the Floor Laughing.
See also: IMHO, TMK.
A router is a special type of internet host that gateways (transfers) packets between two or more networks.
Ruby A scripting language influenced by Perl and Eiffel. Ruby Home Page