This is neither a complicated nor lengthy book; as such, it doesn't need a complicated or lengthy review.
What this book is not: any of the literal thousands of other titles covering networking, vendors, etc, ad naseum of various levels of technical detail and arcane errata.
What this book is: a throughly practical and accessible introduction to Arista switches.
The book is organized into discrete chapters with virtually no dependance on one another: one can skip around to features that are needed today if you're already past the purchasing phase, though there's a non-trivial amount useful for evaluating a purchase as well in this book. Don't need ZTP, skip. No QoS requirements today, come back to it later. Sat through an old Cisco Live (nee Networkers) presentation in 2000 introducing the wonders of crossbar switching fabrics, easy to skim through.
That said, it covers 90% of the bread and butter configuration and even some maintenance / trouble-shooting tasks that commonly occur in a datacenter.
There will almost assuredly be updates of this book in the future, and likely there will be other titles released as Arista attempts to move more into the Enterprise space with their prolific feature release schedule; however, this book is an excellent overview and I encourage folks of pretty much any level approaching Arista for the first time to look at it.
We currently have 25 Arista switches in 2 of our data centers and I have used Arista Warrior on several occasions, ranging from disabling ZTP to allow building a config on new and replacement switches to troubleshooting MLAG issues. This is a must read for any Network Engineer that touches Arista switches on any level. The book is written in the same manner as Network Warrior, with real world examples scattered throughout and actual configurations to assist in your daily operations. Spanning-Tree and QOS are two very well written chapters and after digesting those chapters as well as the rest of this book, I whipped out my knife and carved another notch in my nerd belt.
I was thrilled to see my favorite command included in the book, 'Sho proc top', although it was crammed into the 30th chapter-Troubleshooting. I stumbled across this on my own while troubleshooting a VLAN issue and was amazed when I found the output was in REAL TIME! What? Yes! No more up-arrow, bang enter, repeat, repeat! Hear that Cisco? Glad to see a company like Arista IMPROVE the decades old, monolithic code instead of simply copying the code and bastardizing it like so many others have done before them.
Keep up the good write Gary! Thanks for littering your books with HUMOR, as this helps making this information 'stick', instead of ingesting more dry and mundane techno-babble that most IT books contain.
I think I'll go enter 'Sho donkeys' again!!
I have been working with Arista switches for a while now, this is the manual that should have came with the switches. As the author mentioned, the EOS command syntax is very similar to Cisco IOS. In fact, I have heard of stories where engineers simply copy and paste IOS configuration into EOS during migration and it worked just fine. However, to tap into the capabilities that makes Arista a game-changer one has to get into the realms of SystemDB, Python, Linux user space, etc. Anybody can type commands, but the real challenge lies within the impact and scope of what the commands do. This book does a good job of covering the practical stuff that you can use in your day-to-day, as well as the concepts behind them.
Overall, I would recommend this as a solid investment of money and time for anybody looking into Arista switches.
Pro:
- Real world examples.
- Solid explanation of concepts.
- Sense of humor for an otherwise dry subjects.
Notes, suggestions, erratas:
1. Maybe more coverage into the current fat tree design with spine/leaf/core, etc. This is one area that Arista differs from competitor for the number of ECMP next-hop, tcam division of host routes, etc.
2. Power draw is critically important in large scale data centers, Arista has some good innovation in this area with PHY-less design.
*** Virtual Machines on Arista ***
1. If you don't have an Arista switch handy to practice, or just want a safe environment to practice with, you can run vEOS off a VM: vEOS, [...] by Andre Pech.
2. When you are in a pinch, you can also run another VM direction in EOS: Running Virtual Machines in EOS, [...] virtual-machines-in-eos/ by Mark Berly.
*** sFlow ***
The whole chapter on sFlow probably warrants more coverage. This is one important telemetry tool that offers lots of information and the right direction going forward, IMO. It offers the ability to do push telemetry vs. pull such as SNMP that offers more scalability.
It is also important in the sense of data center billing for the counter. If you are, say, Yahoo and have one of the biggest Hadoop cluster. You would want to know who is your top talker so you can bill them the network overhead accordingly. This is typically done with NetFlow that exports to collector (more on it in a bit), but if you have a network of Arista switches that does not cross the core, sFlow counter is your current best bet.
Because aggregation is done in the onboard flow cache 'before' it sends to collector, NetFlow often falls down in even moderate amount of traffic in data centers. You are forced to scale down on the flow sampling rate that increases the error delta. sFlow on the other hand, just samples and push all the intelligence into the collector.
The author hints at this, but here is an early peak on troubleshooting data plan traffic with sflowtools:
1. Running the open source sflowtools directly on Arista switches for troubleshooting data plan traffic that does not cross CPU. [...]
*** Python ***
Python should have more coverage in the book as that is what Arista CLI is built on. Just some pointers toward motivated Network Engineers which modules to look more into and the location of the files would be helpful.
1. I have asked when Python 3 will be included in Arista, best guess is when Fedora updates their OS to make 3 default.
*** Random Notes about the book ***
1. I think 'sh run all interface' was in 4.7.x, then for some reason went away in 4.8.x, then came back after 4.9.x.
2. I wish the book covers more on the SysDB mount points that Mark Barley points out on EOS Central.
3. IPv6 chapter in the works with 4.10.x code?
4. Nice tip about generating traffic at 'ping -s 15000 -c 10000 10.10.10.15 > /dev/null &' I have done that before but couldn't see the traffic right away and killed it.
5. Why woundn't cron work on Arista (chapter 23)?
6. Nice tips: didn't know that tcpdump can be executed directly from EOS, files other than selected few locations do not survive reloads, emails, etc.
7. ZTP chapter: chapter typo, should be EOS 4.7 and after, not 3.7.
8. ZTP chapter: instead of identifying by mac address, should identify via relay agent or the place of kingdom (show lldl) via script instead of by mac address. The mac address change due to RMA, typo. Also manually mocking DHCP config file does not scale.
9. Event-Handler chapter: More event-handler trigger is indeed needed in Arista in order for the feature to be more useful.
10. Event-Handler chapter: tJust like regular bash script, you can 'demonize' and chain the commands with ';'.
22. Event-handler chapter: There is at least one bug in event-handler in 4.8.3 that configuring 'on boot-up' triggers the event-handler right away. Be careful if the startup script include anything that is production impacting.
23. I like the 'advance usage of sqlite' a lot, gives me some ideas for using sqlite for other features as well. Maybe show the Python integration with sqlite for script purposes?
27. I like what the author pointed out the different between the default flash: location vs. having to specify full Unix path via file: command. I wish I had known this, would've saved me a some time copying stuff from /var/log -> /mnt/flash -> transfer.
28. CloudVision: I wouldn't recommend the use of XMPP in production either. Use the upcoming JSon API instead.
29. Page 360, pretty sure that 'spline' is a typo for 'spine'.
30. Here is a talk by Andy Bechtolsheim in NANOG 55, helps to understand Arista's vision.
Arista warrior gives great view to all of us who are familiar with Cisco and wondered what it would be like to use some different hardware but more importantly some software other than IOS. It answers the questions what's in it for me and not only why should I consider Arista but how I can use their gear better.
I very recently joined Arista in Australia and due to all sorts of reasons, I have to wait several months to do the new hire training.
No problem - I simply bought this book (kindle version) and it has helped me out considerably. I am now recommending this book to any technical person who is the slightest bit interested in Arista or Data Centre Networking.
I love the laconic style and the real world examples of how to make day to day operations so easy compared to what we have been used to.
Great book !
Product Details :
Paperback: 422 pages
Publisher: O'Reilly Media; 1 edition (October 24, 2012)
Language: English
ISBN-10: 1449314538
ISBN-13: 978-1449314538
Product Dimensions: 7 x 0.9 x 9.2 inches
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