Archive

Category Archives for "Systems"

Your Docker Agenda in July

DockerCon 2015 Europe may be a few months away but there are plenty of Docker events and meetups coming up this month near you! Join your local (or online) Docker community to hear firsthand about cool Docker hacks and learn more … Continued

VLAN Trunking with Mikrotik RouterOS

In this post, I’m going to show you how to configure VLAN trunking with Mikrotik RouterOS, and along the way provide a brief introduction to this software and some of the functionality it offers. While it is Linux-based, RouterOS operates quite a bit differently than a lot of the other network operating systems with which I’ve worked, and so I hope that this post will help ease the learning curve a bit for others who decide to take the same path.

Background

First, let me provide a quick bit of background. I found myself in need of a switch that was both Layer 2/3 capable with both 10/100/1000Mbps ports as well as 10Gbps SFP+ ports. Of course, this was for my home lab, so budget is a concern. I cast out a quick call on Twitter, asking for some recommendations, and a few folks recommended I have a look at RouterBoard/Mikrotik; specifically, the CRS-24G-2S+IN (see here for more details). The specs looked good, the price was reasonable, and several folks expressed their satisfaction with the product, so I bought one.

Upon receiving it, I found myself trying to unravel RouterOS (their Linux-based operating system). Their wiki is fairly helpful, but Continue reading

AnsibleFest NYC Networking Automation Panel

Untitled_design-1A few weeks ago at AnsibleFest in NYC, we did something a little bit different: we assembled a panel of networking experts and had a very interesting discussion about some of the challenges and opportunities around networking automation. With representatives from Cisco, Cumulus, World Wide Technologies, and Network to Code, we dug into some of the reasons to automate your network, the technical and organizational challenges, and we reviewed some of the new Ansible modules being written for various networking components. Network automation is an exciting and early area for us, and we are looking forward to what the future holds.

 

A Fix for Ubuntu Apparently Caching Network Configuration

I’ve been wrestling with an Ubuntu network configuration issue over the last couple of weeks (off and on between working on other projects), and today I finally found a fix for the problem. The issue was that Ubuntu wouldn’t pick up changes to network interfaces. The fix is so simple I’m almost embarrassed to talk about it (it seems like something that I should have known), but I’m posting it here in case others run into the same issue.

Here’s a bit more context: I was switching some of the network interfaces in my Ubuntu 14.04.2 servers from a “standard” network configuration to using VLAN interfaces (after all, it seemed like such a shame to not more fully utilize the 10GbE and 40GbE interfaces in these servers). Before the reconfiguration, the servers had a network interface configuration file (located in /etc/network/interfaces.d and sourced in /etc/network/interfaces) that looked something like this:

auto p55p1
iface p55p1 inet static
address 172.16.3.201
netmask 255.255.255.0

This interface was connected to a port on a Cumulus Linux-powered Dell S6000-ON that was configured as an access port on a particular VLAN. Everything seemed to work just Continue reading

VLAN Trunking with Cumulus Linux

Following up on my earlier post on Cumulus Linux networking concepts, I wanted to build on that information with a guide on configuring VLAN trunking. This would be useful in a number of different scenarios: supporting multiple (VLAN-backed) port groups on vSphere hosts, or connecting an Open vSwitch (OVS) bridge on a KVM or Xen hypervisor to multiple VLANs. You might also need to use a VLAN trunking configuration to connect a Cumulus Linux-powered switch to another switch.

For this configuration, I’m going to use the new VLAN-aware bridging functionality introduced in Cumulus Linux 2.5. There are two pieces involved in making this work:

  1. The configuration for VLAN-aware bridge itself
  2. The configuration for the individual port(s)

Let’s look at each of these pieces individually.

The VLAN-Aware Bridge

In order to provide layer 2 (switched) connectivity between front-panel ports on a Cumulus Linux-powered switch, the ports have to be part of a bridge. In this case, we’ll create a VLAN-aware bridge, which simplifies the configuration (in my opinion). It’s a bit less “true” to the Linux way of doing things, but simpler.

Owing to its Debian roots, you’ll configure the bridge by either adding a stanza to /etc/network/interfaces or Continue reading

Wrap-Up: Day 2 of DockerCon 2015

DockerCon 2015 ended yesterday and we’re already missing the energy that was in the air during the conference. Once again, we’d like to thank the over 2100 attendees, 50 speakers and 70+ sponsors who contributed to make this 3rd DockerCon a … Continued
1 … 108 109 110 111 112 … 126