Network documentation 101 ! How? When? Why?

Documentation is an extremely important rule when building a network. You will know what has been done in your network. With a good network documentation, the network support and maintenance procedures could handle the incidents in a more professional and organized way.     Without a good network documentation, there is no map, topology or …

Continue reading "Network documentation 101 ! How? When? Why?"

The post Network documentation 101 ! How? When? Why? appeared first on Cisco Network Design and Architecture | CCDE Bootcamp | orhanergun.net.

Network documentation 101 ! How? When? Why?

Documentation is an extremely important rule when building a network. You will know what has been done in your network. With a good network documentation, the network support and maintenance procedures could handle the incidents in a more professional and organized way.     Without a good network documentation, there is no map, topology or …

Continue reading "Network documentation 101 ! How? When? Why?"

The post Network documentation 101 ! How? When? Why? appeared first on Cisco Network Design and Architecture | CCDE Bootcamp | orhanergun.net.

Noria: dynamic, partially-stateful data-flow for high-performance web applications

Noria: dynamic, partially-stateful data-flow for high-performance web applications Gjengset, Schwarzkopf et al., OSDI’18

I have way more margin notes for this paper than I typically do, and that’s a reflection of my struggle to figure out what kind of thing we’re dealing with here. Noria doesn’t want to fit neatly into any existing box!

We’ve seen streaming data-flow engines that maintain state and offer SQL interfaces and even transactions (e.g. Apache Flink, and data Artisan’s Streaming Ledger for Flink). The primary model here is data-flow, and SQL is bolted on as an interface to the state. The title of this paper sets me off thinking along those lines, but from the end user perspective, Noria looks and feels more like a database. The SQL interface is primary, not ancillary, and it maintains relational data in base tables (using RocksDB as the storage engine). Noria makes intelligent use of data-flow beneath the SQL interface (i.e., dataflow is not exposed as an end-user programming model) in order to maintain a set of (semi-)materialized views. Noria itself figures out the most efficient data-flows to maintain those views, and how to update the data-flow graphs in the face of Continue reading

HiDPI on dual 4K monitors with Linux

I am using a Lenovo Thinkpad X1 Carbon laptop (210 DPI) since four years and a Nokia 8 phone (550 DPI) since a year. I enjoy their HiDPI screens: text is crisp and easy to read. To get a similar experience for my workstation, I bought a pair of Dell P2415Q monitors:

Two Dell P2415Q
Dual screen setup with two Dell P2415Q monitors

Monitors​

The Dell P2415Q is a 24” display featuring an IPS panel with a 3840×2160 resolution (185 DPI) and a complete coverage of the sRGB color space. It was released in 2015 and its price is now below $400. It received positive reviews.

One of my units arrived with a dead pixel. I thought it was a problem from the past but Dell policy on dead pixels says:

During LCD manufacturing process, it is not uncommon for one or more sub-pixels to become fixed in an unchanging state. A display with a 1 to 5 fixed sub-pixel is considered normal and within industry standards.

Another issue is the presence of faint horizontal grey lines, (barely) visible on white background. The issue seems to not be uncommon but Dell is dismissive about it. If I sit correctly, the Continue reading

Ubuntu’s Cosmic Cuttlefish brings performance improvements and more

Canonical has just recently announced that Ubuntu 18.10, code named 'Cosmic Cuttlefish', is ready for downloading at the Ubuntu release site. Some of the features of this new release include: the latest version of kubernetes with improved security and scalability access to 4,100 snaps better support for gaming graphics and hardware including support for the extremely fast Qualcomm Snapdragon 845 fingerprint unlocking for compatible systems (e.g., Ubuntu phones) The new theme The Yaru Community theme -- the theme for Ubuntu 10.18 -- is included with Ubuntu 18.10 along with a new desktop wallpaper that displays an artistic rendition of a cuttlefish (a marine animal related to squid, octopuses, and nautiluses).To read this article in full, please click here

Systemd is bad parsing and should feel bad

Systemd has a remotely exploitable bug in it's DHCPv6 client. That means anybody on the local network can send you a packet and take control of your computer. The flaw is a typical buffer-overflow. Several news stories have pointed out that this client was written from scratch, as if that were the moral failing, instead of reusing existing code. That's not the problem.

The problem is that it was written from scratch without taking advantage of the lessons of the past. It makes the same mistakes all over again.
In the late 1990s and early 2000s, we learned that parsing input is a problem. The traditional ad hoc approach you were taught in school is wrong. It's wrong from an abstract theoretical point of view. It's wrong from the practical point of view, error prone and leading to spaghetti code.

The first thing you need to unlearn is byte-swapping. I know that this was some sort epiphany you had when you learned network programming but byte-swapping is wrong. If you find yourself using a macro to swap bytes, like the be16toh() macro used in this code, then you are doing it wrong.

But, you say, the network byte-order is big-endian, Continue reading

Kernel of Truth episode 9: Layer 3 Networking

Subscribe to Kernel of Truth on iTunes, Google Play, Spotify, Cast Box and Sticher!

Click  here for our previous episode.

For this week’s Kernel of Truth podcast we dive into Layer 3 networking and why we believe it’s the future of network design. In this episode we cover everything about why you should transition to Layer 3, how to make that transition, and why L3 is different than Layer 2. We bring in Jason Heller, a Principle Consulting Architect here at Cumulus, as well as Donald Sharp, a Principle Engineer to gain insight into the future of Layer 3 and the possibilities it can hold for you.

Tune in to to hear the pros and cons of L3 and the best way to begin transitioning and the options that come with Layer 3 networking. If you like what you hear on this week’s episode make sure to follow and subscribe!

Guest Bios

Brian O’Sullivan: Brian O’Sullivan is a generalist who happened to end up in a highly specialized field through no fault of his own. For 15 or so years he’s held software Product Management positions at Juniper Networks as well as other smaller companies. Once he Continue reading

Weekly Show 413: How Disaggregation Accelerates Innovation And Operations With Juniper Networks (Sponsored)

On today's Weekly Show, sponsor Juniper Networks joins us to look at how disaggregation works across the network stack, and how it can drive innovation, operational efficiency, and cost savings.

The post Weekly Show 413: How Disaggregation Accelerates Innovation And Operations With Juniper Networks (Sponsored) appeared first on Packet Pushers.

Weekend Reads ‭190DA‬

By now pretty much all of online advertising is adtech, which doesn’t sponsor publishers. Instead it uses publishers to mark and track eyeballs wherever they might go. It does that by planting tracking beacons (mixed like poison blueberries into those cookies sites now require “consent” to) on readers’ browsers or phones, and then shoots the readers’ eyeballs with ads when they show up elsewhere on the Web, preferably on the cheapest possible site, so those eyeballs can be hit as often as possible within the budget the advertiser has paid adtech intermediaries. @Doc Serls Weblog

Consider, then, that most useful work relies on TCP/IP, which itself relies on the Domain Name System (DNS). We should know as much as possible about our use of the DNS, but most IT administrators are much too busy learning their specialized craft to also become experts on every enabling technology. —Paul Vixie @Dark Reading

The technology products that drive today’s businesses are increasingly produced through a highly diversified and complex international supply chain. Whether it is standard networking gear or a more specialized device like a human-machine interface or remote terminal unit, equipment is often developed through an elaborate web of OEMs, chip makers, Continue reading

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