Create Cisco Switch with IOU [IOS On Unix] Loaded on CentOS

ciscoThe tutorial describes steps required for creating Cisco switch based on IOUl2. The Qemu image with installed CentOS Linux is loaded with IOU image. The IOU (IOS on UNIX) instances are attached to the network using script written by Jeremy L. Gaddis. The script forwards frames between a IOU instance and a Qemu network adapters. The script is started using tap mode when Qemu interfaces are bridged with virtual tap interfaces.

1. Create Qemu image

/usr/local/bin/qemu-img create -f qcow2 ./centos6.0-ioul2.img 2000M

2. Download CentOS 6.0 minimal install CD


Start Qemu image with attached CentOS minimal CD. Read more

PostgreSQL Backup and Recovery with Barman

dbRecently a friend pointed me in the direction of a rather useful piece of software for doing quite funky things with backing up and restoring PostgreSQL databases.

Most organizations I have seen using PostgreSQL and MySQL have always chosen to perform database backups locally on each server. This is fine and it works, but you need to ensure you take a backup of those backup files. I’ve not come across any piece of software that will do complete database backups remotely… that is, until now. This is where “barman” fits in. You can check out what they are all about on the project’s website.

In this article I’ll be going through a really quick howto on getting up and running with Barman in order to perform remote backups of postgresql servers.

In this example I will be using the below details. Read more

Configuring Dovecot to authenticate FreeIPA users using Kerberos (with Single Sign On)

monitorI have also posted this article on the project wiki which is linked here

The below details will walk you through how to add a Red Hat Enterprise Linux 6.2 system to an IPA domain, and then configure Dovecot to allow single sign on to user mailboxes with IMAP/S.

Details of this example are as follows

   Domain name:
   IPA Server:
   Dovecot Server:
   IPA Client:
   IPA User: user1 and user2

Please Note: This guide describes using SSL combined with Dovecot to deliver IMAPS support. This guide is not designed to cover how to create a valid SSL vertificate. This guide uses the default dovecot generated certificate and it is HIGHLY recommended that if you wish to deploy this into a production environment, that you replace this certificate with your own trusted/validated certificate Read more

Deploying Postfix with LDAP (FreeIPA) virtual aliases and Kerberos Authentication

monitorFor those of you looking for a way to set up Postfix so your client base can login with Single Sign On, this article is for you.

Here we will be walking through configuring postfix for the following criteria:

  1. LDAP based User lookups (In this article I have used FreeIPA 3.0)
  2. Single Sign On authentication for mail sending.
  3. Enabling TLS based connections using FreeIPA as the Certificate Authority.

Please be aware that this article does not cover accessing a user’s mailbox as this is covered in the following article.

Before I continue I’d like to thank Loris Santamaria and Anthony Messina from the mailing list for their assistance in getting this solution working.

Details used in this article are as follows:
FreeIPA Servers:,
Postfix Server:
IPA Test user: ipauser1

Read more

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