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Jun 08

Construction Containers (source: Hans).

Originally published on June 1st, 2017 by Brian Anderson of O’Reilly

I recently sat down with Lee Calcote, head of technology strategy at SolarWinds, to talk about the benefits of container networks. Here are some highlights from our chat.

What is container networking? How are people deploying container networks?

Much of what container networking is today revolves around core Linux network technologies, whether that be iptables for port-forwarding, firewalling and network address translation, or ipvs for load-balancing and service abstraction (virtual IP addressing). These battle-tested technologies are old friends of systems engineers, who have leveraged these kernel capabilities as they’ve built container engines and orchestrators.

To date, container networking has largely been focused on simple network services like connectivity, IP addressing (IPAM), (domain) name services, and load-balancing. Beyond connectivity, most higher-level network services—like quality of service (QoS), virtual private networking, security policy (complex and dynamic firewalling), and topology optimization—are still emerging. So far, connectivity has largely equated to use of Linux bridges and network overlays, with VXLAN being a popular protocol. These common choices are in the face of a style of networking that’s arguably more straightforward in its approach: layer 3 networking.

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Sep 16

glen-canyon

Originally published on The New Stack on Sept. 4th, 2016.

There are two proposed standards for configuring network interfaces for Linux containers: the container network model (CNM) and the container network interface (CNI). Networking is complex, and there are many ways to deliver functionality. Arguments can be made as to which one is easier to adopt than the next, or which one is less tethered to their benefactor’s technology.

When evaluating any technology, some important considerations are community adoption and support. Some perspectives have been formed on which model has a lower barrier to entry. Finding the right metrics to determine the velocity of a project is tricky. Plugin vendors also need to consider the relative ease by which plugins may be written for either of these two models. Continue reading »

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Sep 14

container-rope

Originally published on The New Stack on Sept. 4th, 2016.

While many gravitate toward network overlays as a popular approach to addressing container networking across hosts, the functions and types of container networking vary greatly and are worth better understanding as you consider the right type for your environment. Some types are container engine-agnostic, and others are locked into a specific vendor or engine. Some focus on simplicity, while others on breadth of functionality or on being IPv6-friendly and multicast-capable. Which one is right for you depends on your application needs, performance requirements, workload placement (private or public cloud), etc. Let’s review the more commonly available types of container networking.

There are various ways in which container-to-container and container-to-host connectivity are provided. This article focuses primarily on a breakdown of current container networking types, including:

  • None
  • Bridge
  • Overlay
  • Underlay

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