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Category Archives for "Networking"

Small Site Multihoming with DHCP and Direct Internet Access

Cisco recently (15.6.3M2 ) resolved CSCve61996, which makes it possible to fail internet access back and forth between two DHCP-managed interfaces in two different front-door VRFs attached to consumer-grade internet service.

Prior to the IOS fix there was a lot of weirdness with route configuration on DHCP interfaces assigned to VRFs.

I'm using a C891F-K9 for this example. The WAN interfaces are Gi0 and Fa8. They're in F-VRF's named ISP_A and ISP_B respectively:


First, create the F-VRFs and configure the interfaces:

 ip vrf ISP_A  
ip vrf ISP_B

interface GigabitEthernet8
ip vrf forwarding ISP_A
ip dhcp client default-router distance 10
ip address dhcp
interface FastEthernet0
ip vrf forwarding ISP_B
ip dhcp client default-router distance 20
ip address dhcp

The distance commands above assign the AD of the DHCP-assigned default route. Without these directives the distance would be 254 in each VRF. They're modified here because we'll be using the distance to select the preferred internet path when both ISPs are available.

Next, let's keep track of whether or not the internet is working via each provider. In this case I'm pinging 8.8.8.8 via both paths, but this health check can be whatever makes sense for your situation. So, Continue reading

Easy data storage services are like fast food

Recently I made the (unfortunate) decision to eat at a particular fast-food establishment. For the sake of this story, let’s call it Shmurger Shming.I didn’t eat at The Shming because the food tastes amazing. Nor did I choose to ingest those Shmurgers because I thought it was, in any way, healthy for me. In fact, I knew full well that eating them would cause not insignificant amounts of gastronomical distress.Which begs the question: Why, on this green Earth, would I make that decision? Why would I do that to myself?Simple. It was convenient, there was very little up-front investment (in time and money), and it was food. Technically. In other words, I was lazy.To read this article in full or to leave a comment, please click here

Easy data storage services are like fast food

Recently I made the (unfortunate) decision to eat at a particular fast-food establishment. For the sake of this story, let’s call it Shmurger Shming.I didn’t eat at The Shming because the food tastes amazing. Nor did I choose to ingest those Shmurgers because I thought it was, in any way, healthy for me. In fact, I knew full well that eating them would cause not insignificant amounts of gastronomical distress.Which begs the question: Why, on this green Earth, would I make that decision? Why would I do that to myself?Simple. It was convenient, there was very little up-front investment (in time and money), and it was food. Technically. In other words, I was lazy.To read this article in full or to leave a comment, please click here

History Of Networking – Juliusz Chroboczek – Babel Routing Protocol

Babel is a relatively new routing protocol when compared to some of the more well established options, but due to some of its design considerations, it is very well suited for routing on distributed mesh networks. Babel’s creator, Juliusz Chroboczek, joins the Network Collective team in discussing how Babel came about, some of the design decisions when creating it, and what the future looks like for this emerging technology.


Juliusz Chroboczek
Guest
Russ White
Host
Donald Sharp
Host
Jordan Martin
Host

Outro Music:
Danger Storm Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/by/3.0/

The post History Of Networking – Juliusz Chroboczek – Babel Routing Protocol appeared first on Network Collective.

History Of Networking – Juliusz Chroboczek – Babel Routing Protocol

Babel is a relatively new routing protocol when compared to some of the more well established options, but due to some of its design considerations, it is very well suited for routing on distributed mesh networks. Babel’s creator, Juliusz Chroboczek, joins the Network Collective team in discussing how Babel came about, some of the design decisions when creating it, and what the future looks like for this emerging technology.


Juliusz Chroboczek
Guest
Russ White
Host
Donald Sharp
Host
Jordan Martin
Host

Outro Music:
Danger Storm Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/by/3.0/

The post History Of Networking – Juliusz Chroboczek – Babel Routing Protocol appeared first on Network Collective.

Cisco’s IWAN isn’t dead

Earlier this month, Cisco completed the acquisition of SD-WAN vendor Viptela, which it had announced in early May.The companies’ recent news sparked several rumors about the fate of Cisco’s Intelligent WAN (IWAN), with publications writing such articles as “Is the End Near for Cisco’s IWAN?” and “Cisco’s Viptela acquisition could mean IWAN is dying or dead.” The content of the articles isn’t quite as aggressive as the headlines, but the articles have led to a number of misconceptions about what Cisco will do with its SD-WAN solution.To read this article in full or to leave a comment, please click here

Cisco’s IWAN isn’t dead

Earlier this month, Cisco completed the acquisition of SD-WAN vendor Viptela, which it had announced in early May.The companies’ recent news sparked several rumors about the fate of Cisco’s Intelligent WAN (IWAN), with publications writing such articles as “Is the End Near for Cisco’s IWAN?” and “Cisco’s Viptela acquisition could mean IWAN is dying or dead.” The content of the articles isn’t quite as aggressive as the headlines, but the articles have led to a number of misconceptions about what Cisco will do with its SD-WAN solution.To read this article in full or to leave a comment, please click here

38% off Dishonored 2 for XBox One, PS4 and PC – Deal Alert

Play your way in a world where mysticism and industry collide. Will you choose to play as Empress Emily Kaldwin or the royal protector, Corvo Attano? Will you make your way through the game unseen, make full use of its brutal combat system, or use a blend of both? How will you combine your character's unique set of powers, weapons and gadgets to eliminate your enemies? The story responds to your choices, leading to intriguing outcomes, as you play through each of the game's hand-crafted missions. Right now Dishonored 2 is discounted 38% down to $24.99, for the XBOX One, PS4 and PC versions. See this deal on Amazon.To read this article in full or to leave a comment, please click here

Connected IoT is about to become cognitive IoT

Connected devices, also known as the Internet of Things (IoT), will transition to cognitive, predictive computing over the next 12 to 18 months, according to research firm Frost & Sullivan. IoT, overall, is also about to grow rapidly, the firm says. It predicts a 20.3% Compound Annual Growth Rate (CAGR) worldwide leading up to the year 2023. That will be a jump to 45.3 billion devices, up from 12.4 billion IoT devices in 2016, it claims.Cognitive computing, which is when a machine is programmed to simulate human thought processes, will partly drive that growth, along with further microelectronics development and “ubiquitous connectivity,” says Frost & Sullivan, a research and consulting firm that specializes in business disruption.To read this article in full or to leave a comment, please click here

IS-IS Overload Bit – Why IS-IS Overload bit is used ? What are the use cases ?

IS-IS Overload Bit – Why IS-IS Overload bit is used ? What are the use cases ?  In this post, I will explain the Overload bit which is an important feature of IS-IS routing protocol.   When a router which runs an IS-IS routing protocol have resource issue (CPU, Memory), device shouldn’t receive network traffic. […]

The post IS-IS Overload Bit – Why IS-IS Overload bit is used ? What are the use cases ? appeared first on Cisco Network Design and Architecture | CCDE Bootcamp | orhanergun.net.

IDG Contributor Network: How IoT data exchange services will impact IoT development

While the rapid development of the Internet of Things (IoT) has many investors and innovators enamored with hardware development so they can churn out millions of their own IoT-connected devices, wise industry insiders are uncovering the true IoT goldmine: data exchange services. Data sharing, exchanging and selling is rapidly coming to define the IoT market more than anything else, and investors are quickly hopping on board to cash in on this new phenomenon.So how exactly are the industry leaders of tomorrow tapping into data exchange services to fuel their success? How will recent developments in data exchange services impact IoT development, and what steps should sensible IoT developers take now to capitalize on them?To read this article in full or to leave a comment, please click here

IDG Contributor Network: How IoT data exchange services will impact IoT development

While the rapid development of the Internet of Things (IoT) has many investors and innovators enamored with hardware development so they can churn out millions of their own IoT-connected devices, wise industry insiders are uncovering the true IoT goldmine: data exchange services. Data sharing, exchanging and selling is rapidly coming to define the IoT market more than anything else, and investors are quickly hopping on board to cash in on this new phenomenon.So how exactly are the industry leaders of tomorrow tapping into data exchange services to fuel their success? How will recent developments in data exchange services impact IoT development, and what steps should sensible IoT developers take now to capitalize on them?To read this article in full or to leave a comment, please click here

Automation Tools in Building Network Automation Solutions Online Course

A network engineer interested in attending the Building Network Automation Solutions online course sent me this question:

Does the course cover only Ansible, or does it also cover other automation tools like Python?

The course focuses on how you’d build a network automation solution. Selecting the best tool for the job is obviously one of the major challenges, and so one of the self-study modules describes various automation tools and where you could use them to build a full-blown solution.

Read more ...

ReFS integrity is not on by default

I really don’t like the trend of filesystem authors to only care about filesystem integrity by default. How about having seat belt for your data integrity by default and let people turn it off if they want to compromise correctness for performance?

What I didn’t know is that ReFS integrity is not on by default. Only metadata integrity.

It’s also not visible or changeable in the UI (which is why I assumed they’d done the right thing), which is strange to me, this being Windows. No, you have to drop down into Microsoft’s crappy CLI.

How to check if it’s turned on.

Check files in one directory

PS E:\> Get-Item '*' | Get-FileIntegrity

FileName                       Enabled Enforced
--------                       ------- --------
E:\SomeDirectory               False   True
E:\SomeOtherDirectory          False   True
E:\SomeFile.txt                False   True
[...]

Fuck you, Microsoft.

Check recursively

Of course Get-Item doesn’t do recursion. Why would it? That would make sense.

PS E:\> Get-Children -Recurse 'E:\SomeDirectory' | Get-FileIntegrity

FileName                       Enabled Enforced
--------                       ------- --------
E:\SomeDirectory\foo.txt       False   True
[...]

How to enable it

Both commands are needed. The first command sets the new default for the root directory, and the second adds checksums to all existing files and directories.

BrandPost: Cloud Native – The Perfect Storm for Managed SD-WAN Services

We are excited to announce today that Silver Peak has joined MEF. With 130+ members, MEF’s new SD-WAN initiatives are intended to address implementation challenges and help service providers to accelerate managed SD-WAN service deployments. Some of this work involves defining SD-WAN use cases, and a key use case revolves around connecting distributed enterprises and users to cloud-hosted SaaS applications and IaaS.Enterprise CIOs continue to accelerate the pace of corporate digital transformation initiatives, often including plans to migrate enterprise applications to the cloud. Cloud-first is often the preferable choice for hosting new applications, enabling enterprises to securely connect users to applications from anywhere and across any type of WAN service.To read this article in full or to leave a comment, please click here