Switching on the bin

Powerconnect: Configure Link Aggregation Groups

Tue, 16 Jul 2013 00:00:00 +0000

Today we will be configuring LACP to interconnect some switch stacks as part of a network upgrade. Please keep in mind that part of configuring the LAG will result in the ports losing connectivity, so while it is not necessary to use a console cable, please keep in mind how you are connecting to the switch and if you will interrupt that connection by any of your actions, and plan accordingly.

Dell Powerconnect 6200: Enable SSH and Disable Telnet

Mon, 08 Jul 2013 00:00:00 +0000

Most modern switches include the ability to use SSH as a remote communications protocol. Here we will enable that functionality and disable telnet on the Dell Powerconnect 6248 switches.

Enable SSH

In order to enable SSH we need to generate the keys which will be used by SSH to encrypt the traffic.

 text
 
 
console>enable
console# configure
(config)# crypto key generate rsa
(config)# crypto key generate dsa
(config)# ip ssh server
(config)# exit
console# copy running-config startup-config

Disable Telnet

Depending on your config you might not need to disable this, but if it is enabled you should disable it.

Linux KVM: Ubuntu 12.10 with Openvswitch

Wed, 24 Oct 2012 00:00:00 +0000

Today I am revisiting my previous post on Openvswitch on Ubuntu 12.04. Things have changed since then. Previously Openvswitch was relatively new and as such the userland tools (with libvirt being the one I use) didn’t support it yet, so while you could have used Openvswitch by executing the kvm processes for each VM manually. Since this was a predictable problem the Openvswitch guys created a brcompat module, which would take the place of the bridge_utils functionality and expose Openvswitch bridges as legacy bridges. This allowed the existing userland which already had the legacy bridge functionality builtin to continue to operate the same way. Anyways as of libvirt 0.9.11 the native Openvswitch functionality is present and supported. As such I am updating my documentation to include this alternate and preferred method of operation.

Linux-KVM: Ubuntu 12.04 with Openvswitch

Mon, 26 Mar 2012 00:00:00 +0000

UPDATE: October 29, 2012

This article doesn’t work on Ubuntu 12.10, to use Ubuntu 12.10 please refer to my new article here.

Openvswitch is a better way of managing your virtual networking stacks for KVM and Xen. This can be used instead of the bridge-utils package, and has the ability to use VLANs, LACP, QoS, sFlow, and others. In this article we will be using Ubuntu 12.04 (beta1) to configure Openvswitch to hand out networking interfaces to KVM guests.