Network Security and Firewall

Network Security

Networks are growing exponentially, at the same time. They are becoming complex and mission critical, bringing new challenges to network admin who manage that entire network. As per the need of integrated network infrastructure comprising voice, video, and data (all in one) services is evident, but this rapidly growth of Network infrastructure raises a problem such as Network Security. That’s why as network administrator struggle to include the latest technology in their network infrastructure, network security has become a pivotal function in building and maintaining the high growth networks.  

                         

                   In this blog we will just present a brief description of network security in the respect of rapidly changing network environments. The security paradigm is changing, and security solutions today are solution driven and designed to meet the requirements of business. And in a brief would like to discuss about the core principles of Security – the CIA triad: confidentiality, integrity, and availability. And additionally discussing security policies: standards, procedures, baselines, guidelines and various security models and in brief discussing security device PIX and ASA & its simulation with GNS3.

 

Firewall

The Firewall is a device or system those are uses in the network to prevent unauthorized access to or from a private network. Firewall can be employed in the form of hardware as well as software or combination of both.

Or

A firewall is a system of hardware and /or Software that controls access between two or more networks.

Some types of firewall techniques:-

Packet Filtering: 

In this technique FW works on the basis of ACL (Access Control List), FW looks each packet which is entering or leaving the network. Packets are accepted or rejected on the basis of ACL. Packet filtering is fairly effective of transparent to users. A malicious user can still discover what packets meet the FW ACL criteria and send arbitrary traffic Packets can get through by being fragmented Complex Access Control Lists are difficult to configure and camber some to maintain and it is susceptible to IP Spoofing. 

Proxy Service Filtering: 

A proxy server represent a single point of failure for application services, authentication and authorization policy. High degrees of performance over header.Not a scalable solution. Intercepts all messages entering and leaving the network.

Application Gateway: 

Applies security mechanisms to specific applications, such as FTP, Telnet servers. This is very effective, but can impose a performance degradation.

Circuit Level Gateway: 

When the TCP or UDP connection is established , applied this security mechanisms.Once the connection has been established, packets can flow between the hosts without further checking.