Propagating Default Routes - EIGRP

There are 4 ways to get default routes into EIGRP topology. We will take a look at all of them. Consider a simple 2 router topology and let's begin.

Configuring /31 - P2P or Segment with 2 endpoints

In general, most ISPs will assign a /30 on point-to-point interfaces which gives you 4 IP addresses and 2 of which are usable resulting in 50% of addresses in that subnet being wasted. For example 1.1.1.0/30 yields 1.1.1.1 and 1.1.1.2 as your usable IP addresses and 1.1.1.0 is the subnet number and 1.1.1.3 is the broadcast address. And as you can see only 2 out of the 4 IP addresses are usable. So how we can be more efficient? The use of a /31 subnet mask which gives you 2 IP addresses and 100% of them will be utilized.

Consider a very simple topology below and let's get started.

Configuring OSPF FAST hellos

The sooner we detect OSPF neighbor failure the faster the network can converge when there is a failure. In this blogtorial we will see how we can achieve fast detection of OSPF neighbor failure. Consider this simple 2 router topology and let's get started.

Preventing Sub-optimal routing in mutual redistribution - Part 1

Following from my previous redistribution post. Let's explore a few ways we can prevent sub-optimal routing from redistributing routes at multiple routers.

Consider the topology from my previous redistribution post and let's continue.

Configuring Mutual Redistribution - OSPF to RIP

In this blogtorial we will take a look at how to configure mutual redistribution between OSPF and RIP. Though it is very easy to configure, tweaking it and preventing suboptimal routing is tricky. However, we will save "Preventing Sub-optimal routing in mutual redistribution" for the next post.

Consider a very simple topology below and let's get started.

Configuring Frame Relay Point to Point and Point to Multipoint

It has been a while since I have written a blog. I have been very busy with life, new job and my CCIE studies. That's right folks, I have started my pursuit of the digits!! I will post my study materials, my schedule, and study plan on another post. In this blogtorial we will configure Frame Relay Point to Point and Point to Multipoint. We will build on this topology and configure EIGRP and explore topics such as split horizon and see how it affects route advertisments. Consider the simple topology below and lets get started.

Enterprise Campus Design - Part 1

In this blogtorial we are going to dive into how to effectively and efficiently design an enterprise network. As I have always said "Networking is an art not science" as there are numerous ways to design and I am merely posting one of many. 

In this topology we will sink our hands into: 

• STP (802.1d)
• HSRP
• OSPF 
• OSPF route summarization
• VTP
• Different layers/modules of Enterprise Campus Design

Check out the topology below and let's get started. 

Relevant configurations are posted below.

Configuring InterAS MPLS VPNs - CSC (Carriers Supporting Carriers)

In this blogtorial we will take a peek at how to configure InterAS MPLS. InterAS MPLS can be deployed to support customer sites traversing different SPs (Service Providers). 

In this topology we will have 3 customer Sites. 2 of them connection to two different PEs routers in the same AS and another site connected to another PE router in a different AS. 

Topology below and let's get started. 

Relevant configurations are posted below.

How to configure QOS with IPSEC VPN

In this blogtorial we will discuss how to do QOS with IPSec and the challenges that are associated with it. 

Consider the topology below and let's get started. 

Relevant configurations are posted below. 

Configuring MPLS FRoMPLS DLCI-To-DLCI

Recently, I have been posting about AToM (Any transport over MPLS) and to continue I will post how to configure Frame Relay DLCI-TO-DLCI in this blogtorial.

Consider this simple topology and let's get started.

Relevant configurations are posted below.

Configuring MPLS EoMPLS VLAN Mode - L2VPN

In this blogtorial we will configure EoMPLS VLAN mode so we can preserve the VLAN tagging from one site to another. Consider the simple topology and let's get started. 

Relevant Configurations are posted below.

Configuring QEMU (Linux Host) in GNS3

In this blogtorial we are going to see how to configure a Qemu Linux Host. I will keep this simple with screen shots and less words. So let's get started. 

1. Download GNS3 and get it setup. 
2. Download Linux MicroCore image. 

Now follow the screen-shots and you should be good to go.

Configuring DMVPN with OSPF (mGRE and IPSEC)

"I can build you any network you want -- fast/cheap/reliable. Just pick any 2" -- Not sure who said that however  it is true on many levels.

In this blogtorial we are going to take a quick tour on how to configure DMVPN (Dynamic Multipoint Virtual Private Network). So what is DMVPN? DMVPN gives you the ability to create VPN tunnels dynamically as needed between spokes in a hub-to-spoke topology. It can also scale very well to support a large number of remote endpoints. Please keep in mind that DMVPN is Cisco proprietary, however there are ways to implement it using Linux (OpenNHRP).

So here is the topology and let's get started.

Relevant configurations are posted below.

Configuring MPLS Traffic Engineering

In this blogtorial we are going to see how we can configure MPLS Traffic Engineering (MPLS TE). With MPLS TE we can achieve SONET (50ms) style failover between links and we can achieve this by creating backup tunnels and using fast re-route.

In this topology we will be configuring both explicit/static tunnels/paths and also dynamic auto-tunnels. 


Consider the simple topology below and let's get started.

Relevant configurations are posted below.