Errors in Wendell Odom ICND2?

asset

Hi, I was wondering if there is an error in the current (3rd edition) ICND2 written by Wendell Odom? I downloaded the errata for it, but I think there is an error in it(I could be wrong). It states on pg. 210 that Table 5-5 the overlap is the second, third, and fifth, but I see that the forth is also an overlapped. To make a long story short ill just ask the question, maybe I am just too stupid to understand this or just going crazy, but here it is...

Does
172.16.6.0 - 172.16.7.255
and
172.16.6.0 - 172.16.6.255
overlap?
I'm assuming they DO overlap!! Please help me to understand more clearly thanks

Roguetadhg

In my book here's how the example is shown. It uses a combination of 2 tables and 1 figure to piece it together:

The table refers to subnets that overlap with figure in 5-2. (My best attempt at forum topology drawing)

Figure 5-2:
[172.16.2.1/23] Fa0/0 -(R1)- S0/0/1 [172.16.9.1/30] ==Serial Link==> [172.16.9.2/30] S0/0/1 -(R2)- Fa0/0 [172.16.4.1/23]

---

(R1)- S0/1/0 [172.16.9.1/30] ==Serial Link==> [172.16.9.6/30] S0/0/1 -(R3)- Fa0/0 [172.16.5.1/24]

Table 5-4: First Five Possible /23 Subnets
First (Zero) -- 172.16.0.0 > 172.16.1.255
Second -- 172.16.2.0 > 172.16.3.255
Third -- 172.16.4.0 > 172.16.5.255
Fourth -- 172.16.6.0 > 172.16.7.255
Fifth -- 172.16.8.0 > 172.16.9.255

===========================
Table 5-3: Subnets and Address Ranges in Figure 5-2:
R1 Lan: 172.16.2.0 /23 = 172.16.2.0 > 172.16.3.255
R2 Lan: 172.16.4.0 /23 = 172.16.4.0 > 172.16.5.255 SIZE=1][COLOR=#ff0000][I]Overlap with Lan R3[/I][/COLOR][/SIZE
R3 Lan: 172.16.5.0 /24 = 172.16.5.0 > 172.16.5.255 SIZE=1][COLOR=#ff0000][I]Overlap with Lan R2[/I][/COLOR][/SIZE
Serial:
R2 Serial: 172.16.9.1 /30 = 172.16.9.0 > 172.16.9.3
R3 Serial: 172.16.9.6 /30 = 172.16.9.4 > 172.16.9.7

With the ranges written down, refer back to table 5-4...

Table 5-4: First Five Possible /23 Subnets
First (Zero) -- 172.16.0.0 > 172.16.1.255
Second -- 172.16.2.0 > 172.16.3.255 SIZE=1][COLOR=#ff0000][I]Overlaps with R1 Lan[/I][/COLOR][/SIZE
Third -- 172.16.4.0 > 172.16.5.255 SIZE=1][COLOR=#ff0000][I]Overlaps with R2/R3 Lan[/I][/COLOR][/SIZE
Fourth -- 172.16.6.0 > 172.16.7.255
Fifth -- 172.16.8.0 > 172.16.9.255 SIZE=1][I][COLOR=#ff0000]Overlaps with Both serial Links[/COLOR][/I][/SIZE

It states that the second, third, and fifth ranges in Table 5-4 overlap with the existing network ranges.

Fourth range (6.0-7.255) doesn't overlap with any address ranges in the Figure 5-2.

asset

I am sorry to bother with too much questions, but it clearly states figures 5-3 with the last router R3 fa0/0 [172.16.6.1/24]. Btw your topology is good to follow . If then the figure is referring to 5-2 then its correct, but if its referring to fig. 5-3 then its wrong? Thanks

Nate--IRL--

I was going to buy the latest edition of of the OCG when it was due out - but IIRC at the time they had to recall and pulp the first batch of the 3rd edition as it was riddled with errors. You may have gotten a dodgy version maybe?

Nate

Roguetadhg

Im not sure. This is what I see on my page:

"Step 4 compares the information in the table with the existing subnets. In this case, the second, third, and fifth subnets in Table 5-4 overlap with the existing subnets in Figure 5-2."

In my book it's pointing to the right Figure.

Figure 5-3 for me is pointing to the "Designing to use VLSM Subnets"

asset

You are correct!! I think my book has different "Tables", my Table 5-4 is practice problems. I do have figures 5-2 which is correct on my end, but your Table 5-4 is my Table 5-5 lol. The book I have states for figures 5-3 no 5-2. But yes if it did state it for 5-2 then "YOU" are correct. The book I have is the most current edition to my knowledge (3rd edition), and I think it is not perfect Thanks for your time, I guess I am not crazy then

asset

@Nate, you might be right, in fact your right. Thanks again guys/gals for setting me straight

Roguetadhg, thanks for you time. I know its the book now