Firewalls Essay Example | Topics and Well Written Essays - 750 words

Firewalls - Essay Example (2013). Performance and Information Security Evaluation with Firewalls. International Journal Of Security & Its Applications, 7(6), 355-372. doi:10.14257/ijsia.2013.7.6.36 8 A firewall is a device (it could be software or hardware system) that disallows any illegitimate access towards or from a network. (Davis et al.,  2011, p.  xx-xx) Firewalls can be employed in either software or hardware or by combining both of them. Today firewalls are mostly configured to stop unauthorized access from the internet to the private local area networks (LANs) connected with the internet. Firewalls are configured to monitor all the data that enters or leaves the Intranet. It examines every packet and drops those that do not fulfill security standards set by network security engineers. Packet filtering firewall is one of the basic firewall that works on transport and network layer of TCP/IP layering model. (In Vacca,  2014, p.  152-153)A packet filtering firewall monitors packets that are coming in or going out of the network. It accepts or rejects packets on the basis of criteria defined during its configuration. Filtering of packet is pretty effective and transparent to users. One main disadvantage of packet filtering is that it is hard to configure.   1. IP-address of the source. Thick check should be made essentials as most of time IP spoofers change the source IP to show the source of the packet from somewhere else, instead of showing the original source. Application level firewall is generally an application specific firewall. It is configured with a set of application-specific rules that can give control over the network traffic of on the user’s level. (Kizza,  2014, p.  134-135) The main functionality of application layer firewall is to manage internet browsing, filtering emails and its attachment, and transferring of files. Traffic coming inside the network or going outside the network can be denied or allowed on the basis of the different set rules. These rules