• We’re currently investigating an issue related to the forum theme and styling that is impacting page layout and visual formatting. The problem has been identified, and we are actively working on a resolution. There is no impact to user data or functionality, this is strictly a front-end display issue. We’ll post an update once the fix has been deployed. Thanks for your patience while we get this sorted.

CCNA Question.

Page 2 - Seeking answers? Join the AnandTech community: where nearly half-a-million members share solutions and discuss the latest tech.
TCP/IP Networking by Doug Comer is an excellent book ... certainly one of the best available.

It's not OSI specific, but applies the OSI madel as it pertains to TCP/IP.

.02

Scott
 
Originally posted by: TheCause
Every book that Cisco produces is filled with stupid flaws. What kind of group decides that ping is suddenly an acronym anyway!!! AGGGHGHHH! *sigh. There is a book that is publicly available for download that covers Cisco materials. It's a project totaly independant of Cisco Systems.
Click to expand...

what is the name of the book
 
Polm,
Obviously a trick question...the datagram, packet, whatever you want to call it at layer three, contains ALL of the above.

r/ Blaiz :beer:
 
Polm

UDP lives in the Transport layer (4), which you wouldn think might have something to do with flow contro however, UDP does not provide flow control. (B) It is also connectionless (A) and compared to TCP is unreliable (F). These damn things are worded in a way that screws with the mind.

r/ Blaiz

 
Originally posted by: Blaizer2
Polm,
Obviously a trick question...the datagram, packet, whatever you want to call it at layer three, contains ALL of the above.

r/ Blaiz :beer:
Click to expand...

thats not what the book sais. Look above for the books answer.
 
Polm,
If you have CICCO's First Year Companion Guide take a look at Figure 10-9 on pg 386. What did Ciosco say was the right answer?

r/ Blaiz
 
Originally posted by: Blaizer2
Polm,
If you have CICCO's First Year Companion Guide take a look at Figure 10-9 on pg 386. What did Ciosco say was the right answer?

r/ Blaiz
Click to expand...

I don't have that book. I have the latest Cisco Press CCNA Self-Study , and Sybex's CCNA Exam Prep.
 
Originally posted by: spidey07
UDP has acknowledgements...meaning server sends data and client acknowledges data, but it relies on the upperlayer protocol for sequencing.

TCP as a TRANSPORT layer does the sequencing, acks and sliding window, retransmissions for data transfer - the upper layer protocol doesn't need to worry about it, tcp handles it as the transport layer.

So UDP does indeed form a connection on a transport layer - there are PORT numbers involved that when combined with IP addresses create a connection. But it is called CONNECTIONLESS because as a TRANSPORT layer it is not responsible for the retransmission of data.

confusing?

TCP handles the actually transfer of data via sequencing, acknowledgements and sliding windows.

UDP does not, it merely ACKS data.

And that is the key between connection oriented and connection-less oriented transport layers. Most of this stuff becomes stunningly clear when you look at sniffer traces of the various kinds of packets and really see what is going on the wire and get to see each of the OSI layers broken out.

There is a reason that this OSI stuff is ground into network people over and over and over again. Its because it is so dang important and is the very foundation that network communications is built on. Kinda like if you want to be a bridge builder you better know the basic properties of the materials involved and the math as well.
Click to expand...


No offense, but a lot of the stuff you have been saying is dead wrong
 
Originally posted by: rtunez33
Originally posted by: spidey07
UDP has acknowledgements...meaning server sends data and client acknowledges data, but it relies on the upperlayer protocol for sequencing.

TCP as a TRANSPORT layer does the sequencing, acks and sliding window, retransmissions for data transfer - the upper layer protocol doesn't need to worry about it, tcp handles it as the transport layer.

So UDP does indeed form a connection on a transport layer - there are PORT numbers involved that when combined with IP addresses create a connection. But it is called CONNECTIONLESS because as a TRANSPORT layer it is not responsible for the retransmission of data.

confusing?

TCP handles the actually transfer of data via sequencing, acknowledgements and sliding windows.

UDP does not, it merely ACKS data.

And that is the key between connection oriented and connection-less oriented transport layers. Most of this stuff becomes stunningly clear when you look at sniffer traces of the various kinds of packets and really see what is going on the wire and get to see each of the OSI layers broken out.

There is a reason that this OSI stuff is ground into network people over and over and over again. Its because it is so dang important and is the very foundation that network communications is built on. Kinda like if you want to be a bridge builder you better know the basic properties of the materials involved and the math as well.
Click to expand...


No offense, but a lot of the stuff you have been saying is dead wrong
Click to expand...

That's a very constructive 1st post......I'm sure you will go far here!



 
Originally posted by: BS911
Originally posted by: polm
Originally posted by: BS911
Originally posted by: spidey07
I was only trying to help.
🙁
Click to expand...

Yeah i know 🙁
Click to expand...

Please, enlighten us all BS911.
Click to expand...

HUH? What are you talking about?

I said i know Spidey was just trying to help and that guy comes and had to make a negative comment.





😕
Click to expand...


oh, sorry , I mis-read the quotes and thought you had made the rude comment. My bad.
 
You must log in or register to reply here.

TRENDING THREADS

Back
Top