Author Topic: what is firewall?  (Read 1478 times)

wifred

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what is firewall?
« on: August 16, 2013, 03:07:14 AM »
hi

what is firewall?

sreeraj.datasoft

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Re: what is firewall?
« Reply #1 on: August 16, 2013, 03:08:16 AM »
sir,

In computing, a firewall is a software or hardware-based network security system that controls the incoming and outgoing network traffic by analyzing the data packets and determining whether they should be allowed through or not, based on a rule set. A firewall establishes a barrier between a trusted, secure internal network and another network (e.g., the Internet) that is not assumed to be secure and trusted.

afsalabdulla

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Re: what is firewall?
« Reply #2 on: August 16, 2013, 05:35:52 AM »
Hello..

A firewall is a system designed to prevent unauthorized access to or from a private network. You can implement a firewall in either hardware or software form, or a combination of both. Firewalls prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet (i.e., the local network to which you are connected) must pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.

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afsal.datasoft

arjun.datasoft

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Re: what is firewall?
« Reply #3 on: August 21, 2013, 03:48:50 PM »
Hi all,

A firewall is a set of related programs, located at a network gateway server, that protects the resources of a private network from users from other networks.
Basically, a firewall is a barrier to keep destructive forces away from your property.
 In fact, that's why its called a firewall.
Its job is similar to a physical firewall that keeps a fire from spreading from one area to the next.
There are a number of firewall screening methods.
A simple one is to screen requests to make sure they come from acceptable (previously identified) domain name and Internet Protocol addresses.
For mobile users, firewalls allow remote access in to the private network by the use of secure logon procedures and authentication certificates.

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soumya

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Re: what is firewall?
« Reply #4 on: August 28, 2013, 06:47:40 AM »
hello,

A firewall is a software program or piece of hardware that helps screen out hackers, viruses, and worms that try to reach your computer over the Internet.

Windows 7, Windows Vista, and Windows XP SP2 or higher have a firewall built-in and turned on by default.

 It is important to protect every computer. You should have a hardware firewall (such as a router) to protect your network, but you should also use a software firewall on each computer to help prevent the spread of a virus in your network if one of the computers becomes infected.

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Soumya.

hruthika

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Re: what is firewall?
« Reply #5 on: September 09, 2013, 09:15:54 AM »
Hello,

   A firewall is a security device that can be a software program or a dedicated network appliance. The main purpose of a firewall is to separate a secure area from a less secure area and to control communications between the two. Firewalls can perform a variety of other functions, but are chiefly responsible for controlling inbound and outbound communications on anything from a single machine to an entire network

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Hruthika

Rizwan

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Re: what is firewall?
« Reply #6 on: September 19, 2013, 02:16:09 AM »
Hello,

Firewall is a software or hardware-based network security system that controls the incoming and outgoing network traffic by analyzing the data packets and determining whether they should be allowed through or not, based on a rule set. A firewall establishes a barrier between a trusted, secure internal network and another network (e.g., the Internet) that is not assumed to be secure and trusted.

rahesh.datasoft

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Re: what is firewall?
« Reply #7 on: March 05, 2014, 12:01:20 AM »
hai

A firewall is a network security device that grants or rejects network access to traffic flows between an untrusted zone (e.g., the Internet) and a trusted zone (e.g., a private or corporate network). The firewall acts as the demarcation point or “traffic cop” in the network, as all communication should flow through it and it is where traffic is granted or rejected access. Firewalls enforce access controls through a positive control model, which states that only traffic defined in the firewall policy is allowed onto the network; all other traffic is denied (known as “default deny”).


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nithin123@yahoo.com

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Re: what is firewall?
« Reply #8 on: March 23, 2014, 03:03:27 AM »
Hi,

What are the basic types of firewalls?

Nithin

amal@datasoft.ws

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Re: what is firewall?
« Reply #9 on: March 23, 2014, 03:07:05 AM »
Hello,

Conceptually, there are three types of firewalls:

1. Network layer

2. Application layer

3. Hybrids

They are not as different as you might think, and latest technologies are blurring the distinction to the point where it's no longer clear if either one is ``better'' or ``worse.'' As always, you need to be careful to pick the type that meets your needs.

Which is which depends on what mechanisms the firewall uses to pass traffic from one security zone to another. The International Standards Organization (ISO) Open Systems Interconnect (OSI) model for networking defines seven layers, where each layer provides services that ``higher-level'' layers depend on. In order from the bottom, these layers are physical, data link, network, transport, session, presentation, application.

The important thing to recognize is that the lower-level the forwarding mechanism, the less examination the firewall can perform. Generally speaking, lower-level firewalls are faster, but are easier to fool into doing the wrong thing.

These days, most firewalls fall into the ``hybrid'' category, which do network filtering as well as some amount of application inspection. The amount changes depending on the vendor, product, protocol and version, so some level of digging and/or testing is often necessary.


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nithin123@yahoo.com

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Re: what is firewall?
« Reply #10 on: April 04, 2014, 08:53:01 AM »
Hi,

What is source routed traffic and why is it a threat?

Nithin

amal@datasoft.ws

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Re: what is firewall?
« Reply #11 on: April 04, 2014, 08:55:57 AM »
Hello,

Normally, the route a packet takes from its source to its destination is determined by the routers between the source and destination. The packet itself only says where it wants to go (the destination address), and nothing about how it expects to get there.

There is an optional way for the sender of a packet (the source) to include information in the packet that tells the route the packet should take to get to its destination; thus the name ``source routing''. For a firewall, source routing is noteworthy, since an attacker can generate traffic claiming to be from a system ``inside'' the firewall. In general, such traffic wouldn't route to the firewall properly, but with the source routing option, all the routers between the attacker's machine and the target will return traffic along the reverse path of the source route. Implementing such an attack is quite easy; so firewall builders should not discount it as unlikely to happen.

In practice, source routing is very little used. In fact, generally the main legitimate use is in debugging network problems or routing traffic over specific links for congestion control for specialized situations. When building a firewall, source routing should be blocked at some point. Most commercial routers incorporate the ability to block source routing specifically, and many versions of Unix that might be used to build firewall bastion hosts have the ability to disable or to ignore source routed traffic.


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