Cisco CCNA Security 640-553 IINS Tutorials Part-1

Access control list (ACL) ACLs can provide basic traffic-filtering capabilities on Cisco routers. ACLs can be configured for all routed network protocols to filter packets as they pass through a router or security appliance. An ACL may be used for packet filtering (a type of firewall), as well as for selecting types of traffic to be analyzed, forwarded, or influenced in some manner.

Accounting Tracking users’ consumption of network resources. This information may be used for management purposes, planning, billing, or other purposes. Typical information that is gathered includes the user’s name, the nature of the service delivered, when the service began, and when it concluded.

Advanced Encryption Standard (AES) The AES initiative was announced in 1997, when the public was invited to propose candidate encryption schemes to be evaluated as the encryption standard to replace DES. The Rijndael cipher was selected as the AES algorithm in October of 2000 by the U.S. National Institute of Standards and Technology (NIST). In 2002 the U.S. Secretary of Commerce approved the adoption of AES as an official U.S. governmentstandard.

Application layer firewall This third-generation firewall technology evaluates network packets for valid data at the application layer before allowing a connection. Data in all network packets is examined at the application layer and maintains complete connection state and sequencing information. Application layer firewalls also can validate other security items that appear only within the application layer data, such as user passwords and service requests.

Asymmetric algorithm Employs a two-key technology: a public key and a private key. Often this is simply called public key encryption. In this key pair, the public key may be distributed freely, whereas the private key must be closely guarded. If it is compromised, the system as a whole will fail. The way that public key encryption works is that the public key is used to encrypt the data. After it is encrypted, only the private key can decrypt the data. The opposite is also true.