Welcome!

Machine Learning Authors: Elizabeth White, Pat Romanski, Automic Blog, Yeshim Deniz, Jyoti Bansal

Blog Feed Post

MLAG: An Example of Complexity that should not be

In Monday’s blog post, Derick explained the network engineering cycle, traversal in the referential space and the need to provide solutions that enable the network engineer to do his or her job better, more accurate, easier, simpler, more complete. We cannot automate or encapsulate a network engineer’s job and we should not try. We must however encapsulate and automate specific tasks and workflows.

Multichassis Link Aggregation (MLAG) is one of those features that should be so straightforward, but isn’t. MLAG allows a single device to be connected to 2 ethernet switches using a single Link Aggregation Group (LAG). The device is configured with a single LAG with ports that are connected to two switches, rather than a single switch. The two switches coordinate between each other and make it appear to the device as if they are single device.

This part is actually straightforward, it really comes down to using a single LACP system-id across both links from both switches. The end device is blind to the fact there are different switches at the end of each link.

MLAG is Complicated

The hardest part of MLAG is the packet forwarding coordination and behavior between the two switches. For instance, if the end device sends a broadcast packet onto one of the links of the LAG towards switch 1 of the MLAG, the solution must ensure that switch 2 does not send that same broadcast packet back to the end device. Because the two switches together create a LAG, the basic rule that a packet received on a LAG can never be send back out that same LAG must be observed. Sounds simple, but if that broadcast packet gets to switch 2, how does it know it came from the device at the other end of the LAG to begin with? Sounds trivial, just look at the source MAC address, but ethernet forwarding usually does not do anything with a source MAC address.

If a broadcast packet comes in the rest of the network and arrives at switch 1 and 2, who will forward this packet? Only one of them can, again to avoid duplication of packets. Similarly for multicast. In multicast rich environments, would you always pick the same switch to forward this onto the LAG, or would you share that responsibility. And if you share, how do you inform the rest of the network that it is this switch for this specific group that is responsible for distribution?

When one of then links in the LAG fails, what does that switch do with packets towards the end device? How does it get that packet to its MLAG peer so that it is delivered? If you have configured MLAG on any popular platform out there, you have now discovered the reason for the private interconnect between two MLAG peers.

They’re all the same, but different

Whether you call it MLAG, SMLT, VSS, vPC, vLAG or anything else, they all implement the same concept. And there is no question that MLAG is a rather complicated feature to implement and get all the data forwarding possibilities right. There are many failure scenarios to consider to ensure that traffic is not lost, looped, or duplicated.

There is however no reason to expose any of this complexity to you as the user. Why do I have to create a port group between two switches, then explain to each that they are MLAG peers on a special VLAN, then stick IP addresses on this VLAN, create an MLAG peering session, verify it is up and running, then create actual MLAG ports that are mapped to some unique identifier I need to track that needs to match up with the one used on the peer? I counted 24 individual configuration steps just to get the MLAG peering configured.

Why so Complicated?

This is a perfect example of exposing the gory details of the scaffolding required for something that as a user really should be as simple as “I want this port on this and that port on that switch to be part of the same LAG”. Because really that is what you want. Sure, for debugging purposes you may need to understand what is communicated between switches and who has taken responsibility for what, but why did you the user have to manually create all this plumbing between the two systems? That should be encapsulated by us, the vendor, so that you can focus on automating the actual provisioning of ports in an MLAG.

And I completely understand the implementation reasons for having 2 switches matched up to become MLAG peers and MLAGs can only exist between those two peers. But it’s one of those limitations imposed on you that should not be, there is absolutely no reason you could not have 3 MLAG peers. Or 4. Or any combination of 2 switches, different for each MLAG. For us there is no difference between a LAG and an MLAG. That is, there most certainly is a difference, but as far as provisioning one goes, they are identical. You simply configure a LAG. And you have a choice to add ports from other switches to that LAG. And that’s it. All that took was a desire to remove these constraints to make your job easier and more accurate.

Focusing on the user experience of the network takes time, it takes determination, it requires a completely different view on delivering capabilities. Read Derick’s blog post from this past Monday and you will get a sense of our beliefs and approach.

 

[Today's fun fact: Sauerkraut is also a member of the cabbage family and should not be considered an insult (ref: yesterday's fun fact). It is fat free, low in calories, provides about a third of daily needs of vitamin C in a single cup and contains iron, calcium, potassium, thiamin, riboflavin, niacin and 8 grams of fiber. Americans consume 387 million pounds a year, that is more per capita than Germany. And it was first created in the Alsace in France, not Germany.]

The post MLAG: An Example of Complexity that should not be appeared first on Plexxi.

Read the original blog entry...

More Stories By Marten Terpstra

Marten Terpstra is a Product Management Director at Plexxi Inc. Marten has extensive knowledge of the architecture, design, deployment and management of enterprise and carrier networks.

@CloudExpo Stories
SYS-CON Events announced today that Ocean9will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Ocean9 provides cloud services for Backup, Disaster Recovery (DRaaS) and instant Innovation, and redefines enterprise infrastructure with its cloud native subscription offerings for mission critical SAP workloads.
Adding public cloud resources to an existing application can be a daunting process. The tools that you currently use to manage the software and hardware outside the cloud aren’t always the best tools to efficiently grow into the cloud. All of the major configuration management tools have cloud orchestration plugins that can be leveraged, but there are also cloud-native tools that can dramatically improve the efficiency of managing your application lifecycle.
DevOps is often described as a combination of technology and culture. Without both, DevOps isn't complete. However, applying the culture to outdated technology is a recipe for disaster; as response times grow and connections between teams are delayed by technology, the culture will die. A Nutanix Enterprise Cloud has many benefits that provide the needed base for a true DevOps paradigm. In his Day 3 Keynote at 20th Cloud Expo, Chris Brown, a Solutions Marketing Manager at Nutanix, will explore t...
SYS-CON Events announced today that Technologic Systems Inc., an embedded systems solutions company, will exhibit at SYS-CON's @ThingsExpo, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Technologic Systems is an embedded systems company with headquarters in Fountain Hills, Arizona. They have been in business for 32 years, helping more than 8,000 OEM customers and building over a hundred COTS products that have never been discontinued. Technologic Systems’ pr...
SYS-CON Events announced today that CA Technologies has been named “Platinum Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY, and the 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business – from apparel to energy – is being rewritten by software. From ...
The taxi industry never saw Uber coming. Startups are a threat to incumbents like never before, and a major enabler for startups is that they are instantly “cloud ready.” If innovation moves at the pace of IT, then your company is in trouble. Why? Because your data center will not keep up with frenetic pace AWS, Microsoft and Google are rolling out new capabilities In his session at 20th Cloud Expo, Don Browning, VP of Cloud Architecture at Turner, will posit that disruption is inevitable for c...
Deep learning has been very successful in social sciences and specially areas where there is a lot of data. Trading is another field that can be viewed as social science with a lot of data. With the advent of Deep Learning and Big Data technologies for efficient computation, we are finally able to use the same methods in investment management as we would in face recognition or in making chat-bots. In his session at 20th Cloud Expo, Gaurav Chakravorty, co-founder and Head of Strategy Development ...
SYS-CON Events announced today that Cloudistics, an on-premises cloud computing company, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Cloudistics delivers a complete public cloud experience with composable on-premises infrastructures to medium and large enterprises. Its software-defined technology natively converges network, storage, compute, virtualization, and management into a ...
Keeping pace with advancements in software delivery processes and tooling is taxing even for the most proficient organizations. Point tools, platforms, open source and the increasing adoption of private and public cloud services requires strong engineering rigor - all in the face of developer demands to use the tools of choice. As Agile has settled in as a mainstream practice, now DevOps has emerged as the next wave to improve software delivery speed and output. To make DevOps work, organization...
SYS-CON Events announced today that Loom Systems will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Founded in 2015, Loom Systems delivers an advanced AI solution to predict and prevent problems in the digital business. Loom stands alone in the industry as an AI analysis platform requiring no prior math knowledge from operators, leveraging the existing staff to succeed in the digital era. With offices in S...
The explosion of new web/cloud/IoT-based applications and the data they generate are transforming our world right before our eyes. In this rush to adopt these new technologies, organizations are often ignoring fundamental questions concerning who owns the data and failing to ask for permission to conduct invasive surveillance of their customers. Organizations that are not transparent about how their systems gather data telemetry without offering shared data ownership risk product rejection, regu...
What if you could build a web application that could support true web-scale traffic without having to ever provision or manage a single server? Sounds magical, and it is! In his session at 20th Cloud Expo, Chris Munns, Senior Developer Advocate for Serverless Applications at Amazon Web Services, will show how to build a serverless website that scales automatically using services like AWS Lambda, Amazon API Gateway, and Amazon S3. We will review several frameworks that can help you build serverle...
SYS-CON Events announced today that Interoute, owner-operator of one of Europe's largest networks and a global cloud services platform, has been named “Bronze Sponsor” of SYS-CON's 20th Cloud Expo, which will take place on June 6-8, 2017 at the Javits Center in New York, New York. Interoute is the owner-operator of one of Europe's largest networks and a global cloud services platform which encompasses 12 data centers, 14 virtual data centers and 31 colocation centers, with connections to 195 add...
SYS-CON Events announced today that SoftLayer, an IBM Company, has been named “Gold Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2016, at the Javits Center in New York, New York. SoftLayer, an IBM Company, provides cloud infrastructure as a service from a growing number of data centers and network points of presence around the world. SoftLayer’s customers range from Web startups to global enterprises.
Interoute has announced the integration of its Global Cloud Infrastructure platform with Rancher Labs’ container management platform, Rancher. This approach enables enterprises to accelerate their digital transformation and infrastructure investments. Matthew Finnie, Interoute CTO commented “Enterprises developing and building apps in the cloud and those on a path to Digital Transformation need Digital ICT Infrastructure that allows them to build, test and deploy faster than ever before. The int...
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 20th International Cloud Expo, which will take place on June 6–8, 2017, at the Javits Center in New York City, NY. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buyers...
SYS-CON Events announced today that T-Mobile will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. As America's Un-carrier, T-Mobile US, Inc., is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to 67.4 million customers who are unwilling to compromise on ...
@DevOpsSummit has been named the ‘Top DevOps Influencer' by iTrend. iTrend processes millions of conversations, tweets, interactions, news articles, press releases, blog posts - and extract meaning form them and analyzes mobile and desktop software platforms used to communicate, various metadata (such as geo location), and automation tools. In overall placement, @DevOpsSummit ranked as the number one ‘DevOps Influencer' followed by @CloudExpo at third, and @MicroservicesE at 24th.
SYS-CON Events announced today that Infranics will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Since 2000, Infranics has developed SysMaster Suite, which is required for the stable and efficient management of ICT infrastructure. The ICT management solution developed and provided by Infranics continues to add intelligence to the ICT infrastructure through the IMC (Infra Management Cycle) based on mathemat...
Have you ever noticed how some IT people seem to lead successful, rewarding, and satisfying lives and careers, while others struggle? IT author and speaker Don Crawley uncovered the five principles that successful IT people use to build satisfying lives and careers and he shares them in this fast-paced, thought-provoking webinar. You'll learn the importance of striking a balance with technical skills and people skills, challenge your pre-existing ideas about IT customer service, and gain new in...