Head First Networking

Errata for Head First Networking

Submit your own errata for this product.


The errata list is a list of errors and their corrections that were found after the product was released. If the error was corrected in a later version or reprint the date of the correction will be displayed in the column titled "Date Corrected".

The following errata were submitted by our customers and approved as valid errors by the author or editor.

Color Key: Serious Technical Mistake Minor Technical Mistake Language or formatting error Typo Question Note Update



Version Location Description Submitted By Date Submitted Date Corrected
Printed
Page several
index

ISBN is "9780596521554" Several entries in the index refer to incorrect pages. For example: "SSH 335" is acutally on page 333; "WPA 399" is acutally on page 397; "Wireshark, installing 474-475" actually starts on page 472. Looks like the index got out of sync by two pages somewhere. Also, Please see Excercise 1, pg 127. Then compare to Exercise Solution 3, pg 128. This is confusing because it appears the bit is read in the middle of two clock "beats" instead of "at" the clock "beat" as shown in the previous five excercises. Is this correct? Also, A Glossary would be nice (or at least a url to find one; for instance, what is "SSH", "WEP", "WPA") Comment: Very easy read, probably the clearest "networking" book I've ever seen after being my own "network administrator" for a long time.

Note from the Author or Editor:
Multiple Issue: Index is off by 2 pages Issue on exercise is not really an issue, different encoding Add glossary?

Anonymous  Aug 03, 2009 
Printed
Page 13
section 2

Cat5 wire order is named as Standard 568B on page 13, while on page 15 it is named as Standard 586B(A reversal of digits). The name on page 15 agrees with the answer in the crossword on page 36. However this leads me to believe that both standards must be incorrectly named on page 13. I would be curious to know which is correct. Thank-you for accepting this. Steve

Note from the Author or Editor:
568B is the correct nomenclature for pages 13, 15, and the answer on page 48, not 586B.

Steve Cornall  Jan 05, 2010 
Printed
Page 48
Exercise Solution

The exercise on p. 46 asks what type of fiberoptic cable to use if the cable is to be 1300 meters long and carry 1Gbit/sec. The answer given on p.48 is single mode, stating that multimode won't work for this length at this speed. Since the table on page 46 indicates that multimode is good for 2000+ meters and 10 Gbit/sec, and is less expensive, clearly something is wrong here.

Note from the Author or Editor:
This table is not entirely correct on the distances. Figuring distances with fiber is more complex then a simple table, it involves the size of the core, type of light source, etc. This table needs to be replaced.

Ned Taylor  Jan 17, 2010 
Printed
Page 107
Third No Dumb Question

Not sure what the following sentence (last sentence in 3rd A in the No Dumb Questions section) is trying to convey: "But keep reading, there are other tools we haven't covered yet that you really need to see on a wire then?"

Note from the Author or Editor:
Should be "But keep reading, there are other tools we haven't covered yet that you can use to see what is really on the wire."

Anonymous  Oct 16, 2009 
Printed
Page 128
Third answer

1) The diagram below the question is different to the one on the previous page. 2) The note next to it says "This is known as Manchester encoding". That is incorrect. The definition of Manchester encoding is quite specific, and has characteristics that this example lacks. For example - at least one clock change per phase. See http://en.wikipedia.org/wiki/Manchester_encoding The clock change aspect is described in the 'fireside chats' on the next page, but hasn't yet been introduced to the reader.

Note from the Author or Editor:
The charts on the bottom of page 128 and 127 are incorrect. Please see http://en.wikipedia.org/wiki/Manchester_encoding for better descriptions of Manchester Encoding.

Anonymous  Jan 18, 2010 
Printed
Page 145
step 4

"To find comon ASCII codes..." should be: "To find common ASCII codes..."

Note from the Author or Editor:
change comon to common

Anonymous  Oct 17, 2009 
Printed
Page 147, 150
4th exercise question

The fourth question in the "Be the Computer" exercise is different on the exercise page than it is on the solution page. On the exercise page, it's "1 0 _ 0". On the solution page, it's "0 1 1 0"

Note from the Author or Editor:
The second binary code in the right column should be 0110

Anonymous  Oct 18, 2009 
Printed
Page 152
Third No Dumb Question

Second line of second paragraph of third No Dumb Question answer should be "uses an 8B10B..." instead of "uses and 8B10B..."

Note from the Author or Editor:
Second line of second paragraph of third No Dumb Question answer should be "uses an 8B10B..." instead of "uses and 8B10B..."

Anonymous  Oct 18, 2009 
Safari Books Online
155
Expansion of Ethernet payload

The expanded Ethernet payload packet shows a TCP CRC and an IP CRC that follow the TCP header and data. This is wrong, the IP CRC is in the IP header and the TCP CRC is in the TCP header.

Note from the Author or Editor:
Remove IP CRC from lower drawing.

Paolo Galtieri  Jul 18, 2009 
Safari Books Online
158
Sharpen your pencil solution

In the diagram, the content of destination address has been swapped with that of the source address.

Note from the Author or Editor:
The source mac address and destination address on page 158 Sharpen exercise need to be swapped.

Nischal E Rao  Aug 31, 2009 
Printed
Page 159
Sharpen your pencil section

The frames given omit the 'start of frame' byte, and the preamble is too short.

Note from the Author or Editor:
The "captured" frames have incorrect beginnings. The preamble should be 8 bytes long and the start of frame byte is missing. For the sake of keeping the frames short, the preamble should just be removed and a note to effect added.

Anonymous  Jan 18, 2010 
Printed
Page 166
bottom answers

The source hex code to translate is as follows: c0 a8 01 2f It is incorrectly translated as 192.168.1.41. The correct translation is 192.168.1.47 i.e. 0x2f = 47 and not 41

Note from the Author or Editor:
It was an extraneous period that escaped

Douglas Oliver  Jun 26, 2009 
Printed
Page 166
Source IP Address Answer

Source IP Address should end with 47, not 41.

Al Anderson
Al Anderson
O'Reilly Author 
Jan 26, 2010 
Printed
Page 190
"Be the Switch" solution

The "Be the Switch" solution on p. 190 has the switch updating its lookup table on packets sent to the switch (correct) and also on packets sent out of the switch. This is wrong! Packets are either broadcast by the switch (if it doesn't know the correct port for the destination MAC address) or to the single correct port (if it does know). In neither case does the switch update its lookup table for an outgoing message.

Note from the Author or Editor:
The arrows should all point to the switch.

Ned Taylor  Jan 18, 2010 
Printed
Page 202
Exercise solution

In this problem we detect a rogue frame and eventually trace its MAC address to a source that LOCATED ON THE OTHER SIDE OF A ROUTER!! This is not possible. Routers rewrite MAC addresses on frames passing through them. The authors state this themselves on p. 199. I'm going to stop posting errata now although I have others beyond those I've already posted. It's just too depressing.

Note from the Author or Editor:
The Exercise Solution is unclear as to what switch the Learner is connecting to in order to find the rouge MAC address. The rogue packet is tracked through the various routers using the MAC addresses of the sending routers until you get to a switch which will have MAC address in the table. The rouge would have to be constantly sending traffic in order to backtrack and capture traffic on the switch that he is located on.

Ned Taylor  Jan 19, 2010 
Printed
Page 212
Top annotation

There is an extra 1 in the 192 IP Address. It should be 129.168.1.47

Note from the Author or Editor:
Should be 192.168.1.47... Have to fix my own errata submission ;)

Al Anderson
Al Anderson
O'Reilly Author 
Jan 26, 2010 
Safari Books Online
220
Bottom of page

In the sharpen your pencil example on page 220 one of the pair 4 hosts is shown in the listing as 11.48.124.65 but in the answer at the bottom it is shown as 11.48.124.62.

Note from the Author or Editor:
Change the answer to 11.48.124.65

Paolo Galtieri  Jul 18, 2009 
Safari Books Online
228
lower part of the figure

the default gateway to the lowermost device should be 192.168.200.1 instead of 192.168.100.1 (which would be a different network).

Note from the Author or Editor:
Change the default gate address on the computer on the bottom part of the diagram to 192.168.200.1

Anonymous  Sep 02, 2009 
Printed
Page 233
Exercise Answer

The answers are not entirely correct. Here are the correct ones: 172.16.10.1 yes 192.168.100.1 no 204.62.201.12 yes 10.52.1.18 no 172.17.0.3 yes 172.17.0.3 yes 204.62.205.15 yes 172.19.152.42 yes 172.1.0.57 yes Al Anderson, one of the authors

Al Anderson
Al Anderson
O'Reilly Author 
Jun 11, 2009 
Printed
Page 252
Rounter 2's Routing Table

The final line of the table reads 192.168.3.0/24 via 192.168.1.2 Which confuses me because all the other examples on the page have routing via an ip address that is not the router. I.e. the line above reads 192.168.4.0/24 via 192.168.1.1 which makes sense because 192.168.1.1 is on a different router. I think it might be an error but if not am hoping you can fill the gap in my knowledge yours Caoilte Dunne

Note from the Author or Editor:
The last entry on the upper left table is incorrect it should be 192.168.4.1. The bottom entry on the upper right table should be 192.168.2.2. The bottom two entries on the lower right table should be 192.168.2.1 and 192.168.3.2.

caoilte dunne  Oct 08, 2009 
Safari Books Online
277
Bottom of page

in the example for network #4 at the bottom of page 277 it says the network has 52 routers, but in the solution on page 278 it indicates the network has 15 routers. This makes a difference when choosing RIP for your routing protocol given the 15 hop maximum for RIP

Note from the Author or Editor:
The text for network #4 should have the 52 changed to 15

Paolo Galtieri  Jul 25, 2009 
Printed
Page 313
Nameserver Exposed interview

In several spots on page 313, "DNS Nameserver" is incorrectly spelled "DNS Namserver".

Anonymous  Jul 16, 2009