Glossary
GL-2
Cisco Router and Security Device Manager 2.5 User’s Guide
OL-4015-12
ACL access control list. Information on a device that specifies which entities are
permitted to access that device or the networks behind that device. Access
control lists consist of one or more access control entries (ACE).
ACS Cisco Secure Access Control Server. Cisco software that can implement a
RADIUS server or a TACACS+ server. The ACS is used to store policy databases
used by Easy VPN, NAC and other features to control access to the network.
address translation The translation of a network address and/or port to another ne twork address/or
port. See also IP address, NAT, PAT, Static PAT.
ADSL asymmetric digital subscriber line.
aggressive mode A mode of establishing ISAKMP SAs that simplifies IKE authentication
negotiation (phase 1) between two or more IPSec peers. Aggressive mode is
faster than main mode, but is not as secure. See main mode, quick mode.
AES Advanced Encryption Standard
AES-CCMP Advanced Encryption Standard-Counter Mode with Cipher Block Chaining
Message Authentication Code Protocol. AES-CCMP is required for Wi-Fi
Protected Access 2 (WPA2) and IEEE 802.11i wireless LAN security.
AH Authentication Header. This is an older IPSec protocol that is less important in
most networks than ESP. AH provides authentication services but does not
provide encryption services. It is provided to ensure compatibility with IPSec
peers that do not support ESP, which provides both authentication and
encryption.
AH-MD5-HMAC Authentication Header with the MD5 (HMAC variant) hash algorithm.
AH-SHA-HMAC Authentication Header with the SHA (HMAC variant) hash algorithm.
AHP Authentication Header Protocol. A protocol that provides source host
authentication, and data integrity. AHP does not provide secrecy.