Network Warrior

Errata for Network Warrior

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The errata list is a list of errors and their corrections that were found after the product was released.

The following errata were submitted by our customers and have not yet been approved or disproved by the author or editor. They solely represent the opinion of the customer.

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

Version Location Description Submitted By Date Submitted
Printed Page 1
page 80, middle of paragraph 1

The error is in the sentance "To add a VLAN to a trunk we would issue the 'switchport trunk allowed vlan 'vlan-number command'. If this were performed on the switch, ALL VLANs would be REMOVED except the VLAN ID that you just added. This makes for a very bad day.. The correct format should be: "switchport trunk allowed vlan ADD 'vlan-number'. By using this format the VLAN will be added to the existing group of VLANs already residing on the switchport. Good read Gary, thanks for taking such a dry subject and interjecting your real life experiences. Thanks, Glenn Bradley

Glenn Bradley  Feb 02, 2012 
Printed Page 2

Hi, in re-studing routing protocols by this book, and on page 124, regarding rip v2 hops: it sais the max reachable is 255 and unreachable is 256. Its wrong, On rip v1 and v2 the max reachable is 15 and unrechable is 16. Regards, awaiting for the confirmation.

Helder Manuel Rocha Neves  Apr 30, 2012 
PDF Page 9
2nd Paragraph

"A frame enters the network on Hub 1 and is replicated on every port, which includes the two connections to Hub 2, which now repeats the frame out all of its ports, including the two ports connecting the two switches" Shouldn't this be "the two hubs"?

Jason Leschnik  Apr 27, 2017 
PDF Page 9
Figure 2-6

The diagram on the left shows Hub 1 sending Hub 2 a frame on both ports. Wouldn't this just result in a collision on Hub 2?

Jason Leschnik  Apr 27, 2017 
Safari Books Online 9.21

Greetings. Fellow O'Reilly author Jim Van Meggelen here (Asterisk: The Definitive Guide, all 4 versions). You've even mentioned me in your book in chapter 30! (hey thanks!) I was giving your excellent book a read, and I couldn't help jumping to the T1 chapter (because that's what I do), and I had a bit of a heart palpitation when I got there. The information in there is not as clear as it could be, and unfortunately not entirely correct. The first and most important thing to understand is that there aren't really any 'types' of T1 circuits. They are all the same, and are only used in North America. A T1 is a physical circuit used within North America to create a DS1 of 24x64kbps timeslots (twenty-four DS0s). It does not define the protocol carried on top of it. Encoding is part of the T1 (AMI is pretty much never used anymore, it's all B8ZS for the last 15 years from what I've seen). Framing is also part of the T1 (and again I've only really ever seen ESF used for the past 15-20 years or so). If the T1 is up, you can start passing data across it. OSI layer 1 and 2, essentially. Outside of North America, there is no such thing as a T1. The rest of the world uses E1 circuits (very similar to a T1 but instead of 24 timeslots it has 32 timeslots). E1 circuits are also DS1 circuits. Japan has their own circuit type, a kind of hybrid T1/E1 called a J1 (which also is a DS1). OK, now we get to the protocols you can carry on a T1/E1/J1/DS1 (I always tell my guys, before you start trying to get your protocols going, make sure you've got a T1. Can't count the number of times I've had to help some poor soul who was wasting time troubleshooting a D-channel when he didn't even have a solid T1 going). But I digress ... back to protocols you might carry across a DS1: First, PRI: The term 'A PRI' is very confusing to old-school telecom folks, because PRI is a protocol. It's like saying 'A TCP/IP', so it sounds weird to old telecom geeks. PRI is part of the ISDN protocol, which in North America is commonly carried on a single T1 circuit (in fact almost exclusively, but that's not the point). PRI can be delivered in other ways as well (although these days it's pretty rare to see PRI in any format other than 23B+D). As you noted, PRI stands for Primary Rate Interface. However, the full term should be ISDN-PRI, because the protocol in use on a PRI circuit is ISDN. If you've worked in networking you've heard of ISDN Basic Rate Interface (ISDN-BRI), which is the little sibling to PRI (BRI delivers two B-channels of 64K each and a 16k D-channel ... BRI is actually still used in parts of Europe to deliver POTS service). With PRI, there is no restriction on the number of B-Channels and D-channels you can have. If you run PRI across a single T1 (which of course is extremely common) this could be referred to as a 23B+D PRI circuit. However, there are many more combinations possible. In larger PBXs it was common to have 47B+D, or 46B+2D (so as to have a redundant D-channel), or 92B+2D (four T1s with a primary D and a backup D). Or, believe it or not, when PRI first came out we had a few early systems where we ran 24B-channels across the T1, and ran the D-channel on a 56K serial data circuit! (no I'm not kidding, and yes, this did not work well; good thing somebody got clever and figured out how to send the D-channel across one of the B-channels). Outside of North America, there is no such thing as a T1, but they still use PRI. They commonly deliver PRI across circuits known as an E1s. Outside of North America PRI is commonly delivered as 30B+D (but can again be all sorts of combinations of nB+nD). You noted CAS, or Channel Associated Signalling (sometimes named RBS or Robbed-Bit Signalling). There were several different flavours of CAS, intended to behave in a manner similar to older analog PBX trunks (E&M, TIE, DID, etc.). For the most part CAS died out in North America, but in many parts of the world (Latin America for example), they still use those protocols because it is far less expensive. Look up MFC R2 (or R2 signalling), and you'll find yet another use for a DS1. So, to summarize the nature of this erratum: A T1 is a physical circuit unique to the US and Canada. The rest of the planet uses E1s (except Japan, which uses a J1). All a T1 does is deliver a stream of bits back and forth in the form of a DS1. E1s and J1s serve the exact same purpose. What you run on the T1/DS1 (E1/DS1, J1/DS1) is up to you. Popular things to run on DS1s (T1s, E1s and J1s) include the following protocols: ISDN-PRI (23B+D or 30B+D) MFC/R2 (very popular in emerging economies if PRI is prohibitively expensive) CAS FXS (for channel banks) Clear channel (for whatever you want - in your book this is the type of T1 you have configured - no protocol, just raw data using all channels on the circuit to carry any sort of data) CAS DID, E&M, etc (pretty much nonexistent for the past 15 years or so, but theoretically still usable) SS7 (lots of SS7 gets run across DS1 circuits, especially in larger installations where a few hundred DS0s are needed) Not sure if you're doing another edition, but if so, please feel free to reach out to me and I'll be happy to do the technical review on the relevant sections. Probably not really much needs to be said, since these types of circuits are not gaining in popularity. Regards, Jim Van Meggelen

Jim Van Meggelen  Feb 18, 2015 
PDF Page 73
1st command output on page

#### Switch-1-IOS#sho int g3/1 GigabitEthernet5/1 is up, line protocol is up (connected) #### The output should show GigaEthernet3/1 not 5/1 for this command.

Jason Leschnik  May 02, 2017 
Printed Page 112
1st paragraph

The Subnet paragraph indicates that VLSM is covered in more detail in Chapter 34, but it appears that the correct reference would be to Chapter 36.

Toby Ovod-Everett  Jul 12, 2021 
Printed Page 124

On page 124 it says that RIP version 2 has a maximum hop count of 255, but it should be 15.

Anonymous  Mar 08, 2012 
Printed Page 289
2nd paragraph (Here, I'll shut down all the ports....)

On page 287, last paragraph, it is explained to us that each ASIC on a Nexus 7000 controls 4 ports. On page 288 it goes into further detail that the ports each ASIC controls are not contiguous but rather grouped in more of a physical manner. e.g. Top row is one ASIC and bottom row is another ASIC as one can interpret from "a single ASIC controls ports e1/1, 3, 5, and 7, while a different ASIC controls ports e1/2, 4, 6, and 8. The actual error is on page 289 however when it is stated "Here, I'll shut down all the ports in the first port group on module 7, then dedicate the ASIC to the first port." The commands being issued are: int e7/1-4 shut int e7/1 rate-mode dedicated Should that list of commands start with "int e7/1, 3, 5, 7" instead of "int e7/1-4"? Or rather, could it just be "int e7/3, 5, 7"? Since you'll be using e7/1 as the dedicated port I wouldn't see a need to shut it down. Love the book!

Jim Grumbles  Jun 28, 2012 
Printed Page 418
2nd special Note on the page

Be careful when deleting access-lists. If youdelete an access-list that is applied to an interface all traffic will be denied. This is not actually true, All traffic will be allowed when deleting an access before removing off an interface. However it is still be practice to remove first.

Daniel Mohammed  Oct 26, 2013 
Printed Page 472
1st & 2nd paragraph

The command shown in the first paragraph should not be "int g0/0", but "int g0/1" to match Figure 28-1. Likewise, in the second paragraph, the command "int g0/1", but "int g0/0" to match Figure 28-1.

Anonymous  Mar 19, 2012 
Printed Page 566
4th paragaph

For "dial-peer voice 91 voip" at the bottom of page 566, you apply the SIP-Outbound translation profile. However at the top of the page, when configuring "voice translation-rule 2" you strip leading 9s: "rule 1 /^9/ //". This works fine for "dial-peer voice 90 voip" because the destination pattern is "9..........". So CME sees a user dial 9, then a 10 digit number and applies the SIP-Outbound translation profile. However for "dial-peer voice 91 voip" CME would see a user dial 911, which matches the destination pattern of 911, then it will apply the SIP-Outbound translation profile and strip the leading 9. So effectively if someone dials just 911, the digits that get sent out would just be 11. A new translation profile should be created that only includes voice translation-rule 1, to send out 6082222222 as your source/calling number.

Jim Grumbles  May 15, 2013 
Printed Page 598
Page middle - last line of config

> int S0/0 > service-policy output WAN-Edge I believe "WAN-Edge" should be changed to "WAN-Link" which is the policy map defined just above.

Barry Mishler  Jun 21, 2012 
Printed, PDF Page 675
Subnetting range in Subnet Masks -

The bits from bit number 49 to bit number 54 are for defining subnets: 54 should be 64

  Dec 17, 2011 
PDF Page 703
Subnetting Title - First Paragraph

"Because the first 48 bits are reserved for Internet routing, you will likely never have to deal with masks larger than /48 unless you work with Internet routing tables and aggregation. Since the next 8 bits are reserved for subnetting, you will have access to 65,535 subnets with over 18 quintillion devices per subnet for each /48 allocated." Should read: "Since the next 16 bits"

Jason Leschnik  Sep 07, 2017 
PDF Page 704
1st Paragraph

"For reference, a /48 would give you 2 × 10^16 (20,000,000,000,000,000) /64 subnets. I think you can spare a couple for your serial links." This should be 2^16 which gives you 65,536 /64's

Jason Leschnik  Sep 07, 2017 
Mobi Page 5858
2nd paragraph under the "When HSRP isn't enough" section

Text reads: "The routers on either side are connected via the F0/ 1 interfaces, and HSRP is implemented with interface tracking on the F0/ 0 interfaces." Donahue, Gary A. (2011-05-13). Network Warrior (Kindle Locations 5863-5864). O'Reilly Media. Kindle Edition. F0/0 should be S0/0 as shown in the config on the same page below: NY-Primary: interface f0/ 0 ip address standby ip standby preempt standby track Serial0/ 0 10 Donahue, Gary A. (2011-05-13). Network Warrior (Kindle Locations 5867-5869). O'Reilly Media. Kindle Edition. Thus the corrected text would read: "The routers on either side are connected via the F0/ 1 interfaces, and HSRP is implemented with interface tracking on the S0/0 interfaces."

Carl S.  Mar 11, 2013