Security Solutions

A-8
Appendix A: Glossary
DES Data Encryption Standard. A published encryption algorithm that uses a 56-
bit symmetric key to encrypt data in 64-bit blocks. IPSec, the industry standard
for VPNs, supports 3DES. For more information, see FIPS PUB 46-3 at http://
csrc.nist.gov/publications/fips/fips46-3/fips46-3.pdf.
DHCP Dynamic Host Configuration Protocol. A protocol that allows network
administrators to set up a server to manage IP addresses, automatically
assigning IP addresses to devices on the network. DHCP simplifies IP man-
agement, eliminating the need to manually assign IP addresses to devices and
then track those addresses. For more information, see RFC 2131 at http://
www.ietf.org/rfc/rfc2131.txt.
DHCP deployment
method
A deployment method for networks that are not 802.1X compatible. In this
method, the NAC 800 is placed between a switch and a DHCP server and
intercepts DHCP requests from non-tested or non-compliant endpoints. See
also DHCP quarantine method.
DHCP quarantine
method
A quarantine method that gives non-compliant endpoints an IP address in a
quarantine subnet, where they have access only to remediation services.
digital certificate See certificate.
DNS Domain Name Server. A server that associates Internet domain names (such
as www.abccompany.com) with their corresponding IP addresses. Also called
Domain Name System or Domain Name Service, both of which refer to the
protocol and not the physical server.
domain In LDAP, a logical grouping of devices that allows the network administrator
to manage all of the objects in a domain at the same time, for example, to
control who has access to the objects in the domain.
domain controller A Microsoft Windows server that controls activities such as end-user access
in a domain.
domain name
server
See DNS.
DSA Digital Signature Algorithm. A standard for digital signatures that is part of
the DSS. For more information, see FIPS PUB 186-2 at http://csrc.nist.gov/
publications/fips/fips186-2/fips186-2-change1.pdf.
Dynamic Host
Configuration
Protocol
See DHCP.