NetBooz

GNS3 allows the same type of emulation using Cisco Internetwork Operating Systems. It allows you to run a Cisco IOS in a virtual environment on your computer. GNS3 is a graphical front end to a product called Dynagen. Dynamips is the core program that allows IOS emulation. Dynagen runs on top of Dynamips to create a more user friendly, text-based environment. A user may create network topologies using simple Windows ini-type files with Dynagen running on top of Dynamips. GNS3 takes this a step further by providing a graphical environment.

What is Passive attacks

It is common knowledge that when using an untrusted network, such as Internet Café, your communication with the gateway (i.e. a router or access point) must always be treated as untrustworthy.  

The methods available for intercepting users' traffic using a Man-in-the-Middle attack in order to initiate a Passive attack have already been widely discussed.  

For instance, an attacker sets-up an access point with the same network name and MAC address as a genuine one. This gives the attacker complete control over the communication of everyone who mistakenly uses the rogue network instead of the genuine one. This attack is described in the book "Wireless Hacking: Breaking Through "ii. 

Although Passive attacks work well and constitute a serious risk when using a public network, users can protect themselves by following a few general security guidelines, such as:

1. Use SSL as much as possible:

• Avoid logging in to any non-SSL sites

• Make sure the site's SSL certificate is valid

2. If you must access a non-SSL site:

• Do not supply sensitive information: Credit Cards, usernames and passwords.

• Be aware that the integrity of the information you see on such a Web site might have been compromised

• Do not execute applications downloaded from the site

• Do not install software updates, ActiveX controls, browser extensions, etc.

Of course, some of the attack vectors are still valid even if these security guidelines are followed, but the attacker cannot cause much harm, since the user never surfs to any site that deals with sensitive information. 

What is Active attacks

In the Active attack scenario, a malevolent third party manipulates a response within a legitimate session in a way that tricks the client into issuing an unwanted request (unknown to the user) that discloses sensitive information. The attacker can then apply a regular Passive attack on this information. It is important to emphasize that this is made possible by a design flaw, not an implementation error or bug. 

We describe this type of attack as "active" rather than "passive" because of two essential differences in the nature of the attack:

• It is initiated by the attacker rather than the victim 

Before use this commands first check  modem and LAN switch status lights if both are device working fine then cross check cable issue.

Next to open command prompt and check your IP

Win key + R -> RUN -> CMD -> ifconfig or ipconfig

If connection has IP address then ping the default getaway. And make sure its get replay from getaway IP otherwise once cross check your router configuration.

There is next command for checking internet packet path is tracert :-

Problems with a Specific Website

Nslookup is a MX and TXT record finder and website troubleshooting command to check you DNS Server Problems.

There is first difference between Broadband and Leased Line is Prices.

An Internet Leased Line is usually a dedicated line which offers direct connectivity to the Internet e.g. (Atlantic Broadband, Vodafone, Airtel, TATA or your Local ISP provider ) its gives there connection through optical fiber cable, radio links or any combination of direct line from there POP/Nodal point to your end.

In Broadband Internet they give you net from there nearest CP (Center point device) which one placed for multiple user and its not dedicated line or single user its sharing network means device.

In detail about Leased Line connection / Benefit of Leased Line.

  

While there are business broadband options available at pretty good price points, Internet Leased Lines are still preferred with a lot of customers for the following reasons:

Internet Leased Lines offer same speed for both uploads and downloads (symmetric connectivity), while in broadband (through DSL technology) the speeds are always optimized for downloads and the upload speeds are much lesser. Symmetric connectivity is critical for applications like file sharing between two branches, hosting websites/ mail servers etc, video conferencing/ surveillance, voice over IP etc. all of which are used by medium and large businesses regularly.

Generally, broadband connectivity is shared with multiple users in a locality. Broadband plans generally denote the best bandwidth that can be attained and not the assured bandwidth levels. But a 2 Mbps Internet Leased Line should give 2 Mbps of performance as it is a dedicated connection without any sharing.

The backbone network and performance parameters (like latency, jitter etc) can be monitored in the case of Internet Leased Lines. So, it is easier to offer SLA (Service Level Agreements) to the customer and Internet Leased Lines generally come with an SLA. There are very few broadband plans that offer such performance guarantee. So, Internet Leased Lines are more reliable.

There is a wider choice of bandwidth selection (64 Kbps, 128 Kbps,… 2 Mbps,… 155 Mbps etc) with Internet Leased Lines. With broadband, the selection is more restricted.

Higher bandwidth (Greater than 8 Mbps) is possible only through Internet Leased Lines. That’s why it is the default choice for large organizations with hundreds of internet users.

Internet Leased lines are provided through multiple media – Copper, Fiber, Radio links or a combination of the above. Optical media communication is more reliable and offers better fault tolerance/ performance/ monitoring abilities, especially for higher bandwidths.

Internet Leased Lines come with unlimited usage plans which enables companies to add services like video, voice etc over IP in addition to the internet/ data connectivity. Most of the broadband plans offer usage based billing (based on the bandwidth consumed). Of course, there are unlimited usage plans with broadband as well.

Internet Leased Lines offer a pool of permanent IP addresses which enables organizations to run their own mail servers, web servers and other applications.

Internet Leased Lines offer better QoS (Quality of Service) when compared to broadband. So, it is more effective to run convergent services like voice, video etc. over Internet Leased Lines.

Internet Leased Lines can be leveraged to form a Virtual Private Network across multiple branches more effectively than broadband connections.