Configuring OTV - OTV Configuration and Verification

In this blogtorial, I will go through OTV configuration on virtualized routers on Eve-NG and go through a few verification commands. I will also touch on key OTV terminologies and design considerations.

If you need any assistance on how to get Eve-NG up and running on google compute, please see my previous blogtorial - Configuring Eve-NG on Google Compute Engine

Here is the topology. Our goal is to establish layer 2 connectivity between 5.5.5.5 (ESXi-West-1) and 5.5.5.10 (ESXi-East-1). One of the key advantages of using OTV versus other technologies such as VPLS is that spanning-tree domain will not be extended between the sites. Other benefits include ARP suppression, Unknown flooding suppression, Hardware acceleration, and multi path tunneling.

First thing we will configure is the transport network or the underlay. We will start with the devices in the East Site.

High CPU on Nexus 3K - Solved

In this blogtorial, I will demonstrate how I used 'ethanalyzer' on a Cisco Nexus 3K to solve an intermittent issue -- random adjacency drops of various routing protocols. Before we get into the details. let me first share with you on how I got involved in this troubleshooting to begin with. My good friend and colleague "BGP" bill aka self proclaimed "Multicast Guru" 😊 turns around says "Hey Weezy, you are a CCIE right? I have an open case with Cisco for a month why don't you just solve this issue?". Hmmmm ... above all else, one thing I've learned from the journey of becoming a CCIE is that I know very little. There is so much more to learn than you can imagine. In any case, I thought it was a noble challenge and as a bonus it peaked my curiosity. So Bill and I started chatting about the issue and as we were going through the motions, he gave me a great piece of information that would eventually steer me down the path to solving the issue, "Pete reported that he saw HIGH CPU usage compared to other similar routers".

So my 2 questions were:

ip multicast helper-map - Converting Broadcast and Multicast

If you work in the financial industry you are bound to encounter a situation where you will have an application that publishes udp data as broadcast and you will need to convert it to multicast -- maybe even back to broadcast if needed. This is very similar to the "ip helper address" because "ip helper-address" converts DHCP (udp) to unicast packets and sends it to the DHCP server.

Couple of very important roles of the routers in this setup are FHR and LHR. First-hop router that is connected directly to the source which is broadcasting the data and the Last-hop router that is connected to the destination subnet which can convert the multicast back to broadcast. 

Consider this simple topology and let's get started. 

Complete configs can be found here.

Converting Multicast to Unicast

In my previous blogtorial "Converting unicast to multicast" we discussed how to convert unicast to multicast and what the benefits are. Suppose that for one reason or another we had to convert from multicast to unicast -- how would we go about doing that? Well in this blogtorial we'll do just that.

Let's get started.

In this scenario, R2 will convert multicast coming in on Fast1/0 and convert it to unicast on Fast1/1.

Complete configs can be found here.

Converting Unicast to Multicast

Imagine that you had to do a presentation in front of an audience. Would it make sense to stand on a stage and give the presentation or sit with each individual and repeat the presentation multiple times? Well obviously standing on the stage and giving the presentation once to many audiences is much more efficient – this concept in networking is referred to as one-to-many multicast. One stream distributed to multiple receivers is just one of the advantages of running multicast on your network. If there are many receivers listening for one stream, there is no need for the server to send the same stream to multiple destinations – just use multicast.

But what if the server is running an outdated software and can not do multicast? No worries, today we are going to see how we can convert unicast into multicast. This blogtorial assumes that the reader is somewhat familiar with multicast concepts and configurations such RP, IGMP and PIM.

Here is our objective:

• Software BuiBui residing on Comp1 is sending unicast data.
• Instead of Comp1 wasting bandwidth and sending the same data to Comp4 (C4) and Comp5 (C5), we need to convert the unicast to multicast data and forward it to Comp4 (C4) and Comp5 (C5).

Consider the topology below and let’s get started.

Complete configs can be found here.

BGP - Configuring mBGP (Multicast BGP)

Do you influence or do you manipulate people to get what you want? What exactly is the difference? I mean in the end, you end up getting what you want right? Wrong, The difference lies in loyalty, if you influence someone then you get them to want to do what you want them to do. If you coerce or manipulate you may achieve short term success, however in the long term you will loose their trust and they will perceive you as someone who violated their trust rather than a leader. Therefore a great leader will influence others to achieve long term success. Although, sometimes you have no choice but to manipulate, for example my wife wants to influence me to do the dishes. Well that's just not going to happen -- she's never going to convince me that I want to do dishes, so she settles for manipulation :). Now that we've gotten my daily tidbit out of the way let's get into the topic at hand which is -- mBGP (Multicast BGP) not to be confused with Multi-protocol BGP which is used by MPLS, IPv6 etc.

Imagine you have Unicast Servers and Multicast Sources on the same network. Furthermore, imagine that you have 2 paths to reach that network, however you want to separate Unicast and Multicast traffic between different paths. How can we achieve this? Well there are a couple of options.

One, we can add static mroutes downstream or you could run mBGP and since the title of this blogtorial is configuring mBGP we'll choose the latter option. 

Consider this simple topology and let's get started. 

Complete configs can be found here.