Azure & Cross-Host Container Networking using Rancher


Today we’ll try to understand a bit more about the Rancher cross-host networking capabilities.


Rancher supports cross-host container communication by implementing a simple and secure overlay network using IPsec tunneling. To leverage this capability, a container launched through Rancher must select “Managed” for its network mode or if launched through Docker, provide an extra label “–label”. Most of Rancher’s network features, such as load balancer or DNS service, require the container to be in the managed network.

Under Rancher’s network, a container will be assigned both a Docker bridge IP ( and a Rancher managed IP ( on the default docker0 bridge. Containers within the same environment are then routable and reachable via the managed network.

Note:The Rancher managed IP address will be not present in Docker meta-data and as such will not appear in the result of a Docker “inspect.” This sometimes causes incompatibilities with certain tools that require a Docker bridge IP. We are already working with the Docker community to make sure a future version of Docker can handle overlay networks more cleanly.

Source :

So in short… You can create a virtual network spanned accross all hosts using Rancher. At the time of writing, this is still based upon an IPsec VPN implementation underneath, where RancherLabs is looking to implement the “new” overlay networking of the native Docker. Be aware that Weave is also pretty known, and used, within the community. Though at this point I want to keep it as simple as possible…

High Level Setup

Anyhow, let’s look at our labo for the day…


Continue reading “Azure & Cross-Host Container Networking using Rancher”

Azure : Deploying Point-to-site VPN

This post will provide you with a high level outline how to set up a point-to-site VPN with an Azure virtual network. If you run into issues during the setup, browse to the last part of this post, as it contains some “gotchas” that we encountered in the past.

Point-to-Site VPN Setup
Browse to your virtual network, then “configure” and tick the “Configure point-to-site connectivity”…
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Next up is to enter the local ip range your client devices will receive upon connection!
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Client Connector
Now press save and upon success, you will find the download links of the VPN connector on the dashboard page.
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Before you ask… there are NO non-windows agents available for download.

Authentication Configuration
In regards to the authentication, this is solely done via certificates. So I advise you to follow this guide

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The guide will get you through the process of creating a root certificate and generating client certificates by using this root certificate. Along with the VPN software, you’ll be providing your users/partners/… an export of the client certificate. In turn, they will need to import this into their workstation.

The bumps on the road…
What are the issues you’ll run into?

  • Makecert? I don’t have this… Download the SDK and install the “Windows Software Development Kit. Afterwards you’ll find “makecert” in %Programfiles%\Windows Kits\8.1\bin\x86|x64.
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  • I installed the vpn software. What now? – The install runs and a terminal windows flashes. 2015-09-03 10_40_57-RD-APOC-VDC02Now you are in the dark… Not nice of Microsoft to be honest! Browse to “Control Panel”, “Network & Internet”, “Network & Sharing Center” and then “Connect”. Now you will see your VPN connection. If you have no connect button, go to “Set up a new connection or network”, select “Connect to a workplace” and select your VPN adapter… 2015-09-03 10_42_00-Connect to a Workplace Next is to connect to the VPN … 2015-09-03 10_42_23-RD-APOC-VDC02 and validate the functionality! 2015-09-03 10_42_49-Network and Sharing Center

I hope this helped you on your journey in Azure!