Enterasys Networks ANG-1100 manual Ethernet, Firewall

Appendix A

Glossary

authentication server (such as a RADIUS or SecurID server). When the network administrator changes tunnel connection parameters, the Aurorean Policy Server provide updated configuration files to Aurorean Network Gateways on request.

DHCP

Dynamic Host Configuration Protocol (DHCP) servers are used to assign IP addresses. The Aurorean Network Gateway-1102/1105 is capable of assigning IP addresses.

DSL

Refers to Digital Subscriber Lines. DSL technologies use sophisticated modulation schemes to pack data onto copper wires. They are sometimes referred to as last-mile technologies because they are used only for connections from a telephone switching station to a home or office, not between switching stations. Usually the maximum distance between the home or office and the switching station has to be around one mile.

Ethernet

The Ethernet originated in 1974 by Xerox to connect many office machines together to allow communications between them. Coax cable was originally used. today twisted pair wire can be used and the speeds can be up to 10 megabits per second.

Firewall

A combination of hardware and software which limits the exposure of a corporate network to outside attack by enforcing a boundary between the network and the Internet. Firewalls normally fall into one of two categories: application-level or network-level (often referred to as a packet filter). An application-level firewall examines traffic at the application level, and only passes packets that are sent by approved applications (such as FTP, E-mail, or Telnet). This type of firewall often readdresses outgoing traffic so that it appears to have originated at the firewall rather than an internal host, thereby concealing the address of the internal host. A network-level firewall examines traffic at the network packet level, and filters packets based on the destination and/or source address.

42 Aurorean Network Gateway-1100 User’s Guide