How to set up Zimbra mail server on CentOS

In this tutorial, we will examine the process of installing Zimbra mail server in CentOS Linux environment. Zimbra is my personal favorite when it comes to open-source mail servers as it comes with a number of useful features such as built-in calendar support, email filtering rules, a modern interface for both users and admins, spam […]
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How to migrate Cacti to a new server

Cacti is a popular network graphing tool widely used by many service providers. For those of you who have been using Cacti to visualize the performance of various elements of your network, it is sometimes necessary to migrate Cacti and all its graph datasets from one server to another. Why? The current server may be […]
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How to connect your LAN to Amazon Virtual Private Cloud

If you have a lot of your services hosted in the Amazon AWS public cloud, and are looking for ways to access your leased AWS resources in a secure way, this article is for you. Initially you started out accessing Amazon AWS over the public Internet. Over time, you have migrated more and more services […]
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How to combine two graphs on Cacti

Cacti is a fantastic open source network monitoring system that is widely used to graph network elements like bandwidth, storage, processor and memory utilization. Using its web based interface, you can create and organize graphs easily. However, some advanced features like merging graphs, creating aggregate graphs using multiple sources, migration of Cacti to another server […]
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How to secure BGP sessions using authentication on Quagga

The BGP protocol runs over TCP, and as such, it inherits all the vulnerabilities of a TCP connection. For example, within a BGP session, an attacker may impersonate a legitimate BGP neighbor, and convince the BGP routers on the other end to share their routing information with the attacker. The problem occurs when the attacker […]
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How to perform BGP traffic engineering using Quagga on Linux

The previous tutorials demonstrated how we can turn a CentOS box into a BGP router and filter BGP prefixes using Quagga. Now that we understand basic BGP configuration, we will examine in this tutorial how to perform more advanced traffic engineering on Quagga. More specifically, we will show how we can influence the routing path […]
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How to set up IPv6 BGP peering and filtering in Quagga BGP router

In the previous tutorials, we demonstrated how we can set up a full-fledged BGP router and configure prefix filtering with Quagga. In this tutorial, we are going to show you how we can set up IPv6 BGP peering and advertise IPv6 prefixes through BGP. We will also demonstrate how we can filter IPv6 prefixes advertised […]
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How to filter BGP routes in Quagga BGP router

In the previous tutorial, we demonstrated how to turn a CentOS box into a BGP router using Quagga. We also covered basic BGP peering and prefix exchange setup. In this tutorial, we will focus on how we can control incoming and outgoing BGP prefixes by using prefix-list and route-map. As described in earlier tutorials, BGP […]
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How to turn your CentOS box into a BGP router using Quagga

In a previous tutorial, I described how we can easily turn a Linux box into a fully-fledged OPSF router using Quagga, an open source routing software suite. In this tutorial, I will focus on converting a Linux box into a BGP router, again using Quagga, and demonstrate how to set up BGP peering with other […]
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