LSA issue @ February 2, 2017 at 10:28PM

It is remarkable how quickly technology giants like Facebook, Google, Amazon and others became newsmakers No1 in the networking area. Seriously, for 5 breaking news from these guys its only 1 serious announcement from vendor-camp. Keeping the ratio in favor of tech giants meet the roundup of the recent Facebook' even called Disaggregate: Networking. [1]

Last week Facebook held an invitation-only party with very few companies onboarded, among which were Barefoot, Apstra, Canonical and Cumulus. At Facebook, we build our data centers with fully open and disaggregated hardware. This allows us to replace the hardware or the software as soon as better technology becomes available. Because of this, we see compute, storage, and networking gains that scale with our business. We spoke about our latest networking hardware and software — including Wedge 100, Backpack, Voyager, FBOSS and OpenBMC.

As you see, the key topic of this event was disaggregation between software and hardware components. I urge you to watch the keynote video as it lays out the vector of the whole event and helps one to understand why disaggregation was mandatory to large-scale companies like FB.

Here is the list of the talks happened there:
– Managing a Hybrid Network [by FB] (Don't spend too much time on this talk, it is about Robotron tool, which is much better explained in this deicated article [2])
– Wedge100 and Backpack: From the Leaf to the Spine [by FB]– Why Forwarding Planes will be Programmable: New Paradigms and Use Cases in Networking [by BAREFOOT] (exceptional talk by Barefoot on what is P4 programmable chip and its benefits)
– Open Networking Landscape Overview [by BigSwitch]– Disaggregating The Network OS With Ubuntu [by Canonical]– OpenBMC: An Open Software Framework for BMC [by FB]– Experiences Deploying Disaggregated Solutions [by Cumulus]– The Disaggregated Network Stack [by Snaproute]– Making Open Networking Easy to Build, Deploy and Operate [by Apstra]– Voyager: Opening Layer-1 [by FB]– Network Emulation: Testing Switch Software at Scale [by FB]

#Video #Facebook #Automation

[1] http://ift.tt/2jMwVJs
[2] http://ift.tt/2k4ZSk5
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LSA issue @ January 28, 2017 at 02:35PM

A burden of many #NETCONF articles and tutorials is that they are often silent about the #YANG part. This is why we would like to highlight this post by Michael Kashin called ""Getting Started With NETCONF and YANG"" [1]. Not only this article covers the basics of network elements configuration via NETCONF (particularly via python ncclient module [2]) but also extends to the YANG models definition with practical examples.

Michael uncovers how heavily NETCONF relies on YANG models, how one can download models straight from a network element itself and how to repsent YANG models in a human-readable tree-view with pyang [3] support.

In its closing you'll see a little bit more advanced technique of building a python module based on the downloaded YANG models. Later this python module is used to create a configuration XML delivered via NETCONF to the network element resulting in a configuration change.

And if you are intereseted in NETCONF, make sure to check a NETCONF package for ATOM [4] which allows you easily compose and deliver NETCONF commands to the network elements and the Yang-Explorer tool to visually examine YANG models [5]

#Article #Automation #NETCONF #YANG

[1] http://ift.tt/2kEkgdn
[2] http://ift.tt/2kDS85X
[3] http://ift.tt/2bBSXwI
[4] http://ift.tt/28Z8gKx
[5] http://ift.tt/2kElsxf
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LSA issue @ January 23, 2017 at 10:41AM

It is always tempting and interesting to see how big guys do their networks. We saw some pieces from Google, Facebook, Amazon, LinkedIn and now Twitter comes. Big 5 is all set!

Last week engineering force at Twitter released an article titled ""The Infrastructure Behind Twitter: Scale"" [1]. The article starts off with networking field in focus and covers both DC and Backbone challenges Twitter faced over the time.

Data Center story is no surprise at all, IGP started to give more troubles that benefits and was swapped with ""BGP as IGP"" solution. Classics of modern DC design. By the way, there is a bonus track in the DC section of the article — a nice slide deck explaining how Twitter did this migration on a live network [2].

At the Backbone side Twitter surpisingly had no TE at some point (o.O). Now they most certainly do and they also adopted TE++ from Juniper [3] which helps them overcome bin-packet problem (common problem for Big 5, Facebook had this as well). After all RSVP-TE autobandwith has some serious players that have implemented it.

When it comes to Edge, problems like PoP design and steering traffic to PoPs start to pop out. Serving a customer from a closest point available (less RTT means less delay and more goodput) is a corner stone for worldwide scale players. On the latter case Twitter ditched geo-DNS in favor of BGP-anycast. We saw this done by LinkedIn and Facebook [4],[5]

Though from a birds eye view all the probles are the same we should thank Twitter for sharing! Maybe we'll see more goodnes from their Engineering dept. soon.

#Article #Datacenter #RSVPTE #BGP

[1] https://blog.twitter.com/2017/the-infrastructure-behind-twitter-scale

[2] http://ift.tt/2iXOVjR

[3] http://ift.tt/2iXSNBg

[4] https://www.youtube.com/watch?v=LPCbKzhvAGc

[5] http://ift.tt/2jnKpsp
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LSA issue @ January 19, 2017 at 10:43AM

Here is the question: if Host A wants to transmit some data across TCP/IP network to Host B with IP address of 1.2.3.4 how will this Dest_IP address be represented?

Correct, it will be hex encoded, but will the bytestream be like 0x01 02 03 04 or 0x04 03 02 01? Yep, you see where I am going, its endianness who is telling us which byte comes first.

So take a look at this short article which is a perfect read on Endianness. It uncovers why x86 CPUs (back in 90-00's) were a bad choice for networking equipment and how the hell Gulliver's Travels has mixed up with all of it?

#Article #TCP

http://ift.tt/2k2Q6vX
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LSA issue @ January 1, 2017 at 02:13PM

Hey there, engineers! Its January 1st 2017 and we are happy to welcome you and wish you all the best.
But is it 2017 indeed? How would one tell if his clock is good, if its in sync with the world clock? Yeah, you got it, in the era of the leap second and New Year eve what topic could we bring up if not NTP?

Lucky us, an Australian SRE@Canonical Paul Gear wrote a 5-post long topic called ""The School for Sysadmins Who Can’t Timesync Good and Wanna Learn To Do Other Stuff Good Too"". We bet you'll become grandmaster of NTP once you read all five of them!

#Article #NTP #Synchronization

Part 1 — The problem with NTP: http://ift.tt/2ivmx9b

Part 2 — How NTP works: http://ift.tt/2iSgk3y

Part 3 — NTP install and configure: http://ift.tt/2ivnUVu

Part 4 — Monitoring and Troubleshooting: http://ift.tt/2iSlPiN

Part 5 — Myths, misconception and best practices: http://ift.tt/2ivmwC9
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LSA issue @ December 13, 2016 at 10:24AM

Here is your fresh IPv6 fix: Tenth iNOG, namely iNOG::A, is all about IPv6 experience.
Technical talks are:
1) Orla McGann (HEAnet) An Irish IPv6 Fairytale
2) Nathalie Trenaman (RIPE) The Sad Tale of 462 Operators Who Switched Off IPv6* (*with a happy ending)
3) Ed Horley (Groupware Technology) IPv6 Operating Challenges

Particulary interesting talk was given by Nathalie from RIPE who was talking about IPv6 global perception seen from RIPE point-of-view.

#Video #iNOG #IPv6

https://www.youtube.com/watch?v=WSH6jxmqrag
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LSA issue #December 9, 2016 at 02:27PM

There is a popular saying that you don't need to be a programmer to automate your network. Might be true, though you definitely won't succeed in automation tasks without basic Regular Expressions knowledge, that you should take for granted.
Sad thing that regular expressions are not an easy nut to crack, and with this post we would like to share with you useful resources that will help you meet and greet RegExps!

#TipsTricks #Programming

http://ift.tt/xGwhyj — Mastering Regular Expressions, 3rd Edition.

http://ift.tt/1vDrJcd — a free and massive tutorial on RegExps

http://ift.tt/2fOuDYM — regexps collection for different tasks

https://regex101.com/ — the best online regexp engine to test and validate your regexps

http://ift.tt/1OR8EKT — solving regexps just for fun

http://ift.tt/1T6FiJy — book a place on your desk to hang this RE cheatsheet
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