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Thread ID: 127556	2012-10-30 08:16:00	Computer science question: IP address schema, access control method in ethernet+ CSMA	icow (15313)	PC World Chat

Post ID	Timestamp	Content	User
1309704	2012-10-30 08:16:00	I'm having the write a report type thingy (super technical I know...) on various aspects of a local area network. I've got most of it sorted but there are a few things which I hope someone here might be able to better explain than text books. First thing I'm not too sure about is IP address schema. I understand you have 3 main network classes A, B and C. Each using different amounts of bits from the IP addresses for the network and the host depending on the network class but I'm not too sure why you would need different classes of networks, I assume some lend themselves better to different network structures or scales? Can someone give an explaination as to why you would use a certain network class? I need to discuss this as well as the positives and negatives of dynamic and static IP addresses as well. This is something I don't have any idea at all about. Personally I have just gone with what seems to work with the hardware I'm dealing with apart from in certain situations (opening NAT for example). I can see an obvious positive for static being you each computer/device has its own IP so various actions should be able to traced back to it and that you could have specific settings for each computer (unblocking ports for internet connection, not that this is related to LANs?) but other than that I'm lost as to why you would use dynamic IP's. Any ideas? Also I need to discuss how access control method(s) are used in ethernet architecture and how they can/are used to manage network traffic (in a LAN). Is this MAC? And lastly I have to discuss how collisions occur in CSMA/CD and how they are managed with the CSMA/CD protocol. Also discussing acceptable levels of collisions and how difficulties experienced with the CSMA/CD protocol are overcome with the use of ethernet switches. I personally have not had to discuss CSMA/CD at any point until now, so I have next to no idea as to what it does (specifically). Any help on this topic would be great. Any help will be greatly appreciated.	icow (15313)
1309705	2012-10-30 11:56:00	What is the report for? This looks very much like homework questions. ...I'm not too sure why you would need different classes of networks, I assume some lend themselves better to different network structures or scales? Can someone give an explaination as to why you would use a certain network class?These days, you wouldn't. Pretty much every router / device / application on the planet now supports CDIR (en.wikipedia.org), which renders class-based networks redundant. I need to discuss this as well as the positives and negatives of dynamic and static IP addresses as well. This is something I don't have any idea at all about. Personally I have just gone with what seems to work with the hardware I'm dealing with apart from in certain situations (opening NAT for example). I can see an obvious positive for static being you each computer/device has its own IP so various actions should be able to traced back to it and that you could have specific settings for each computer (unblocking ports for internet connection, not that this is related to LANs?) but other than that I'm lost as to why you would use dynamic IP's. Any ideas?Think of scaling - imagine how difficult it would be to manage a large organisation's network, or an ISP, if everything had to be individually configured with a static address. Also consider servers, routers etc - what would happen if the IP address of your router or a server you were connecting suddenly changed? Also I need to discuss how access control method(s) are used in ethernet architecture and how they can/are used to manage network traffic (in a LAN). Is this MAC?No - MAC is a system for addressing ethernet frames. Some access-control methods are based on filtering or logging frames based on their MAC address, but there are many more which have nothing to do with it. And lastly I have to discuss how collisions occur in CSMA/CD and how they are managed with the CSMA/CD protocol. Also discussing acceptable levels of collisions and how difficulties experienced with the CSMA/CD protocol are overcome with the use of ethernet switches. I personally have not had to discuss CSMA/CD at any point until now, so I have next to no idea as to what it does (specifically). Any help on this topic would be great.Do some research into ethernet hubs, and why these are now avoided wherever possible. That should answer most of your questions about this particular part. Any help will be greatly appreciated.Hopefully the above was useful - feel free to ask if you have more questions.	Erayd (23)
1309706	2012-10-30 12:43:00	Re MAC - having re-read your question I'm wondering if this (en.wikipedia.org) is what you're talking about - could you please clarify what exactly you're wanting to know here?	Erayd (23)
1309707	2012-10-31 06:36:00	What is the report for? This looks very much like homework questions. It's a new NCEA standard. Meaning it's likely full of stuff which is too easy or too hard and doesn't have the appropriate amount of credits attached to it :/ All the things I'm asking here also have a specific context/scenario that they need to be applied to. could you please clarify what exactly you're wanting to know here? This is exactly what is written on the paper/mark schedule "Discussed how the access control method used in Ethernet architecture manages Ethernet traffic on a LAN." Will ask if there is a more descriptive version of that next time I'm in class. Going to deal with the CSMA bit tonight. Will keep you posted if I have any questions. Hopefully the above was useful - feel free to ask if you have more questions. Certainly was, thanks :)	icow (15313)
1309708	2012-10-31 14:10:00	It's a new NCEA standard.Oh dear... Good luck with it :thumbs:.	Erayd (23)
1309709	2012-10-31 20:04:00	I get the feeling this 'standard' is based on some fairly old documentation... newer network technologies tend to remove the need for CSMA/CD etc.	inphinity (7274)
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