Cumulus Linux in the enterprise campus.

As most know, Cumulus Linux was originally intended for data center switching and routing but over the years, our customer base has requested that we expand into the enterprise campus feature set too. Slowly, we’ve done just that.

With this expansion though, there are a few items that IT managers tend to take for granted in an all Cisco environment that may need some extra attention when using Cumulus Linux as a campus switch. This is especially the case when it comes to IEEE 802.1x, desk phones, etc.

Most of the phones we inter-operate with have been of the Cisco variety and quite often, those phones are connected to Cisco switches. There are a few tweaks from the default Cumulus settings that need to be called out in this environment and we’ll now go over what those are and how you can tweek them.

Cisco IP Phones TLV change

Cisco IP phones may revert to a different VLAN after initial negotiation. One of our enterprise customers found that according to a Cisco tech note on LLDP-MED and CDP, CDP should be disabled on non-Cisco switches connecting to Cisco phones.

To eliminate this behavior, make the following adjustment to the Continue reading

Weekend Reads 120618

Paris Traceroute allows you to deterministically measure particular paths by setting particular flow IDs — effectively setting combinations in packet headers to be treated consistently by routers on a path. Using this trick to run many traceroutes with different flow IDs to a target may reveal an entire topology, but without extra logic, it may involve tens of thousands of traceroute packets to do so. Many of those packets will be sent over hops that never change, making those packets redundant while also consuming bandwidth and time. —Kevin Vermeulen @APNIC

So, when people talk about serverless, what does it mean? Well, it doesn’t mean servers are GONE. Of course not: That “client-server model” is still the backbone of how things are getting done. Serverless refers to a developer’s ability to code, deploy, and create applications without having to know how to do the rest of it, like rack the servers, patch the operating system, and create container images. —Jen Wike Huger @opensource.com

The average size of Distributed Denial of Service (DDoS) attacks — where attackers seek to take down a website, application, or infrastructure by flooding it with requests — increased by 24% in 2018. In addition, the attack Continue reading

Stuff The Internet Says On Scalability For December 7th, 2018

Wake up! It's HighScalability time:

Do you like this sort of Stuff? Please support me on Patreon. I'd really appreciate it. Know anyone looking for a simple book explaining the cloud? Then please recommend my well reviewed (31 reviews on Amazon and 72 on Goodreads!) book: Explain the Cloud Like I'm 10. They'll love it and you'll be their hero forever. And if you know someone with hearing problems they might find Live CC very useful.

 

Weekly Show 419: Benchmarking Public Cloud Network Performance With ThousandEyes (Sponsored)

You need to know a cloud provider's network performance before you spin up workloads because the end user impact is measurable. On today's Weekly Show, sponsor ThousandEyes breaks down latency, jitter, and performance numbers for AWS, Azure, and GCP.

The post Weekly Show 419: Benchmarking Public Cloud Network Performance With ThousandEyes (Sponsored) appeared first on Packet Pushers.

Future Thinking: Orla Lynskey on Data in the Age of Consolidation

Last year, the Internet Society unveiled the 2017 Global Internet Report: Paths to Our Digital Future. The interactive report identifies the drivers affecting tomorrow’s Internet and their impact on Media & Society, Digital Divides, and Personal Rights & Freedoms. We interviewed Orla Lynskey to hear her perspective on the forces shaping the Internet’s future.

Orla Lynskey is an associate professor of law at the London School of Economics and Political Science. Her primary area of research interest is European Union data protection law. Her monograph, The Foundations of EU Data Protection Law (Oxford University Press, 2015), explores the potential and limits of individual control over personal data, or “informational self-determination’” in the data protection framework. More recently, her work has focused on collective approaches to data protection rights and mechanisms to counterbalance asymmetries of power in the online environment. Lynskey is an editor of International Data Privacy Law and the Modern Law Review and is a member of the EU Commission’s multistakeholder expert group on GDPR. She holds an LLB from Trinity College, Dublin, an LLM from the College of Europe (Bruges) and a PhD from the University of Cambridge. Before entering academia, she worked as a competition lawyer in Brussels Continue reading

Hair-pining in a Wide Area Network – Simple Design Scenario

In this post we will discuss how hair-pining is occurring in some topologies in the Enterprise  branch sites, when connecting to 2 Service Providers, while the 2 Service Providers are not directly connected to each other and don’t have any MPLS/VPN Inter-AS Option (A,B,C,..) with each other. From the customer side, some of the remote …

Continue reading "Hair-pining in a Wide Area Network – Simple Design Scenario"

The post Hair-pining in a Wide Area Network – Simple Design Scenario appeared first on Cisco Network Design and Architecture | CCDE Bootcamp | orhanergun.net.

Visibility plays critical role in a successful SD-WAN deployment

The rise of SD-WANs has been well documented by every analyst firm that covers network technology. I have the market growing from $1.0 billion in 2017 to over $9.5 billion in 2022, indicating the market is about to go through an accelerated phase of growth. Given SD-WANs can help save money and improve network agility, it seems like a no-brainer to evolve to an SD-WAN.However, the path to an SD-WAN isn’t easy. There are a lot of factors to be considered, including the use of broadband, how to optimize the links, network architecture, and the impact of moving the on-premises infrastructure out to the cloud. If anything is missed, application performance could be severely degraded, which would negate the return on investment of the project.To read this article in full, please click here

Visibility plays critical role in a successful SD-WAN deployment

The rise of SD-WANs has been well documented by every analyst firm that covers network technology. I have the market growing from $1.0 billion in 2017 to over $9.5 billion in 2022, indicating the market is about to go through an accelerated phase of growth. Given SD-WANs can help save money and improve network agility, it seems like a no-brainer to evolve to an SD-WAN.However, the path to an SD-WAN isn’t easy. There are a lot of factors to be considered, including the use of broadband, how to optimize the links, network architecture, and the impact of moving the on-premises infrastructure out to the cloud. If anything is missed, application performance could be severely degraded, which would negate the return on investment of the project.To read this article in full, please click here

It’s The Change Freeze Season

Everyone’s favorite time of the year is almost here! Is it because it’s the holiday season? Perhaps it’s the magic that happens at the end of the year? Or maybe, it’s because there’s an even better reason to get excited!

Change Freeze Season!

That’s right. Some of you reading this started jumping up and down like Buddy the Elf at the thought of having a change freeze. There’s something truly magical about laying down the law about not touching anything in the system until after the end-of-year reports are run and certified. For some, this means a total freeze of non-critical changes from the first of December all the way through the New Year until maybe even February. That’s a long time to have a frozen network? But why?

The Cold Shoulder

Change freezes are an easy thing to explain to the new admins. You simply don’t touch anything in the network during the freeze unless it’s broken. No tweaking. No experimenting. No improvements. Just critical break/fix changes only. There had better be a ticket. There should be someone yelling that something’s not right. Otherwise you’re in for it.

There are a ton of reasons for this. The first is Continue reading

What is an SSD? How solid state drives work

That whirring you hear when you boot your computer or when it wakes from sleep mode is the sound of your hard drive’s magnetic disks beginning to spin. Conceptually not dissimilar to a record player, a hard disk drive (HDD) is an electromechanical device with an actuator arm that positions itself over spinning disks, called platters, in order to read or write information.While record players top out at 78 rpm, today’s enterprise-grade HDDs can spin at 15,000 rpm. Even at that speed, however, there are unavoidable delays associated with heads finding the spot on the drive that contains the data being requested. And sometimes a drive may need to read from multiple locations in order to complete a command, multiplying wait times.To read this article in full, please click here

What is an SSD? How solid state drives work

That whirring you hear when you boot your computer or when it wakes from sleep mode is the sound of your hard drive’s magnetic disks beginning to spin. Conceptually not dissimilar to a record player, a hard disk drive (HDD) is an electromechanical device with an actuator arm that positions itself over spinning disks, called platters, in order to read or write information.While record players top out at 78 rpm, today’s enterprise-grade HDDs can spin at 15,000 rpm. Even at that speed, however, there are unavoidable delays associated with heads finding the spot on the drive that contains the data being requested. And sometimes a drive may need to read from multiple locations in order to complete a command, multiplying wait times.To read this article in full, please click here

Using Virtual Labs When Developing Network Automation Solutions

One of the fundamentals I always emphasize in introductory parts of my network automation workshops and online courses is the fact that we’re about to develop software that will control the most-mission-critical part of IT infrastructure, and should therefore use software development methodologies like version control, testing…

However, there’s a “small” glitch. While it’s perfectly possible to test most software in some virtual environment you can spin up on-the-fly using Vagrant, Docker, Jenkins, Travis, or some other CI/CD tool, testing a network automation solution requires access to network devices.

Read more ...

RapidChain: scaling blockchain via full sharding

RapidChain: scaling blockchain via full sharding Zamani et al., CCS’18

RapidChain is a sharding-based public blockchain protocol along the lines of OmniLedger that we looked at earlier in the year. RapidChain is resilient to Byzantine faults from up to 1/3 of its participants, requires no trusted setup, and can achieve more than 7,300 tx/sec with an expected confirmation latency of roughly 8.7 seconds in a network of 4,000 nodes with a time-to-failure of more than 4,500 years. Those are pretty interesting numbers!


(Enlarge)

RapidChain partitions the set of nodes into multiple smaller groups of nodes called committees that operate in parallel on disjoint blocks of transactions and maintain disjoint ledgers.

With n nodes, each committee is of size m = c \log n where c is a security parameter typically set around 20. E.g. with 1,000 nodes we’ll have around 17 committees of 60 nodes each. To make all these work we’ll need a number of different parts:

  • A way to bootstrap the initial system
  • A way of forming (and re-forming) committees, and allowing nodes to join and leave
  • A way of reaching consensus within a committee (shard)
  • A way of verifying transactions which cross-shards

Bootstrapping

The initial set of participants start Continue reading

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