preview

Firewalls And Infrastructure Security

Good Essays

Firewalls and Infrastructure Security

A firewall is a network device, hardware, software, or a combination of the two, whose purpose is to enforce a security policy across its connections. It is comparable to a wall that has a window where the wall serves to keep things out, except those permitted through the window. A security policy acts like the glass in the window; it permits some things to pass, light, while blocking others, air. The heart of a firewall is the security policy that it enforces.
Security policies are a series of rules that define what traffic is permissible and what traffic is to be blocked or denied. These are not universal rules, and there are many different sets of rules for a single company with multiple …show more content…

Advanced firewalls employ stateful packet filtering to prevent several types of undesired communications. Should a packet come from outside the network, in an attempt to pretend that it is a response to a message from inside the network, the firewall will have no record of it's being requested and can discard it, blocking access. As many communications will be transferred to high ports, above 1023, stateful inspection will enable the system to determine which sets of high communications are permissible and which should be blocked. The disadvantage to stateful inspection is that it takes significant resources and processing to do this type of inspection and this reduces efficiency and requires more robust and expensive hardware. This type of inspection is essential in today's comprehensive networks. As they are in routers, switches, servers, and other network devices, Access control lists are a cornerstone of security in firewalls. Just as you must protect the device from physical access, Access control lists do the same task for electronic access. Firewalls can extend the concept of Access control lists by enforcing them as well at a packet level when packet-level stateful filtering is performed. This can add an extra layer of protection, making it more difficult for an outside attacker to breach a firewall.
Some high-security firewalls also employ application layer proxies. As the name

Get Access