Dynamic Host Configuration Protocol allows network administrators to centrally manage and automate
the assignment of IP addresses on the corporate network. DHCP sends a new IP address when a
computer is plugged into a different place in the network. The protocol supports static or dynamic IP
addresses and can dynamically reconfigure networks in which there are more computers than there are
available IP addresses.
DNS
A Domain Name Server is used to translate domain names to IP addresses. Although the Internet is
based on IP addresses, names are easier to remember and work with. All these names must be
translated back to the actual IP address and the DNS servers do so.
DoS attack
Denial of Service attacks occur when a critical network or computing resource is overwhelmed so that
legitimate requests for service cannot succeed. In its simplest form, a DoS attack is indistinguishable
from normal heavy traffic. ExtremeXOS software has configurable parameters that allow you to defeat
DoS attacks.
DSA
Digital Signature Algorithm is a Federal Information Processing Standard for digital signatures. It was
proposed by the National Institute of Standards and Technology (NIST) in August 1991 for use in their
Digital Signature Standard (DSS) and adopted as FIPS 186 in 1993. Four revisions to the initial
specification have been released: FIPS 186-1 in 1996, FIPS 186-2 in 2000, FIPS 186-3 in 2009, and FIPS
186-4 in 2013.
DSSS
Direct-Sequence Spread Spectrum is a transmission technology used in Local Area Wireless Network
(LAWN) transmissions where a data signal at the sending station is combined with a higher data rate bit
sequence, or chipping code, that divides the user data according to a spreading ratio. The chipping
code is a redundant bit pattern for each bit that is transmitted, which increases the signal's resistance to
interference. If one or more bits in the pattern are damaged during transmission, the original data can
be recovered due to the redundancy of the transmission. (Compare with
EAP-TLS/EAP-TTLS
EAP-TLS Extensible Authentication Protocol - Transport Layer Security. A general protocol for
authentication that also supports multiple authentication methods, such as token cards, Kerberos, one-
time passwords, certificates, public key authentication and smart cards.
IEEE 802.1x specifies how EAP should be encapsulated in LAN frames.
In wireless communications using EAP, a user requests connection to a
through an access point, which then requests the identity of the user and transmits that
identity to an authentication server such as
RADIUS (Remote Authentication Dial In User Service)
The
server asks the access point for proof of identity, which the access point gets from the user and then
sends back to the server to complete the authentication.
EAP-TLS provides for certificate-based and mutual authentication of the client and the network. It relies
on client-side and server-side certificates to perform authentication and can be used to dynamically
generate user-based and session-based
WEP (Wired Equivalent Privacy)
keys.
Glossary
ExtremeSwitching 200 Series: Administration Guide
356
