Sub-Subnet

[k0mbachi]

Here's a question from the Sybex CCNA study guide with which I have issues. Would anyone care to provide their answer selection and analysis for this question? I'll post a couple of potential answers later.

Identify the network and host portions of the IP address 172.19.241.36, given the subnet mask 255.255.255.0.

A. Network 172; host 19.241.36
B. Network 172.19; host 241.36
C. Network 172.19.241; host 36
D. Network 172.19.241.36; host 241.36

 

[ecafracs]

Network 172.19.241; host 36

172.19 - class B
subnet- 255.255.0.0
w/ 8 bits used for subnetting - 255.255.255.0
254 subnets with 254 hosts each

actually the real answer would be
network - 172.19
subnet-241
host 36

 

[k0mbachi]

ecafracs: Your answer, C, is what's listed as the correct answer. However, I was thinking of the Class B and subnet breakout. I guess the lesson here is, in Ciscospeak, subnets are a part of the network if the correct option isn't presented. Thanks for the feedback.

 

[nohair]

Hi,
The answer would be C. Thenetwork portion is defined by the subnet mask. There is only 2 parts to an IP address, network/subnet part and host part. There is no such thing as network / subnet / host except in an IP schema diagram


BR,

-Stephen

 

[bierhunter]

ecafracs. Excellent explanation.

nohair,
Techically, there is a network/subnet/host definition. However, in today's ip classless society, it has pretty much been accepted as network/host. With the network being a combination of network and subnet. But, it is still a class-B network of 172.19 with a subnet of 241 and host of 36. It's just that nobody really looks at it that way anymore, because we are all so used to being classless.

As far as the question goes, answer C would be correct. But, be wary of Sybex sample questions. When taking the real test, always look very closely at the wording of the question. Some questions may be speaking in classful terms, and others in classless terms. I've noticed that Sybex doesn't have very good study material. At least in my experiences. The main thing is to read the real question very carefully and answer in a classful or classless manner as per the question's wording.

 

[k0mbachi]

bierhunter: With all of the pretest apprehension, I have had situations where Lammle (Sybex) provides lucid detail where Odom's book has been a bit "flowery". There are probably situations where the reverse is true as well. I'm delighted to have been able to include both books in my study arsenal.

 

[bierhunter]

Using multiple books is an excellent idea. I do that as well. Ever since I switched to using the Cisco press books, I've started noticing more errors in some of the others especially Sybex. But, it also depends upon which author wrote the book too, so I shouldn't really put all Sybex books into the same category.

If it works for you, then by all means, stick with it. The final outcome is what's important.

 

[k0mbachi]

Whether the process works, or not, is still being determined. What really felt progressive was upgrading a 2505 PROM, DRAM and IOS this morning! The old IOS didn't have IPX, ISDN and probably other commands.

Does anyone know if the Cisco Flash Card package includes questions that are different from the Odom book and the ESIM lab?

 

[balaganesh]

try

http://www.net130.com

you'll get loads of 'em.

Ganesh --Ganesh
TopGun Technologies

http://www.topguntechnologies.com