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I always mess up with the basic concepts in networking. This are the very basic questions.
- What is a router, its functions and what is meant by routing?
- What is a switch, its functions? Many time I heard that there are layer 3 switches. If there are layer three switches , why they are not called as router? since they are doing work of a router. What is the exact difference by which we decide this router and this is switch?
- What is a hub?
I have read about these questions plenty of time and then to I have messed up in my interviews. Please let me know or give me a link to study about these things in very detail.
1Have you tried Wikipedia? If so, what concepts don't you understand, specifically? Maybe tried, you know, Google? Google Suggest autocompletes "level 3 switch" with "vs router", and the first result delivers, AFAICT. If you read about these topics, and you know what aspects you didn't understand fully for your interview, you should be able to form much better, much more specific questions. – Daniel Beck – 2011-05-20T07:40:23.343
1Seconded. If you have "read about these questions plenty of time" then you wouldn't have to ask what a router, a switch and a hub is. You should do your research first and then ask specific questions. Many people won't provide you with more than Wikipedia has to offer (yes, they have some useful articles) – slhck – 2011-05-20T08:08:40.820
4Honestly, I can see how the Wikipedia articles could be confusing to someone facing these basic questions. Take a look at them. Here's the lead for the Hub article: "An Ethernet hub, active hub, network hub, repeater hub or hub is a device for connecting multiple twisted pair or fiber optic Ethernet devices together and making them act as a single network segment. Hubs work at the physical layer (layer 1) of the OSI model.[1] The device is a form of multiport repeater. Repeater hubs also participate in collision detection, forwarding a jam signal to all ports if it detects a collision." – Louis – 2011-05-20T09:12:21.763
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@Louis Continues: "A network hub is a fairly unsophisticated broadcast device. Hubs do not manage any of the traffic that comes through them, and any packet entering any port is regenerated and broadcast out on all other ports. Since every packet is being sent out through all other ports, packet collisions result—which greatly impedes the smooth flow of traffic." Everything one needs to know, really. Regarding the difference search for "hub" in the Switch article, linked from the Hub article in "see also".
– Daniel Beck – 2011-05-20T09:18:40.0602
If the terminology on Wikipedia is too complex, there is always the option of the Simple English Wiki. While not having as much content as the main english wiki, it can help for easier understanding of the topic (although, for example, don't expect it to have an explanation on quantum physics).
– tombull89 – 2011-05-20T09:24:12.673Whether questions with answers on Wikipedia are OK has come up a few times: http://meta.stackexchange.com/questions/5280/embrace-the-non-googlers http://meta.stackexchange.com/questions/7441/can-and-should-more-be-done-to-encourage-users-to-search-first-and-ask-only-if http://meta.stackexchange.com/questions/8724/how-should-we-deal-with-google-questions http://meta.stackexchange.com/questions/33376/is-it-bad-to-ask-google-searchable-questions-on-stack-overflow http://meta.stackexchange.com/questions/3734/how-long-should-i-search-for-an-answer-before-i-ask-on-stackoverflow-and-friends
– hippietrail – 2011-05-20T13:18:17.413Most of the time , I feel details in wikipedia are too complex. Explanation itself contains a lot of technical terms. As a starter, sometimes it is very difficult to understand. I have to refer further wikipedia pages to understand them and most of the time it leads to a series of pages. I want something simpler. – narayanpatra – 2011-05-20T14:41:59.353