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Combining MLAG Clusters with VXLAN Fabric

In the previous MLAG Deep Dive blog posts we discussed the innards of a standalone MLAG cluster. Now let’s see what happens when we connect such a cluster to a VXLAN fabric – we’ll use our standard MLAG topology and add a VXLAN transport underlay to it with another switch connected to the other end of the underlay network.

MLAG cluster connected to a VXLAN fabric

MLAG cluster connected to a VXLAN fabric

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Repost: On the Viability of EVPN

Jordi left an interesting comment to my EVPN/VXLAN or Bridged Data Center Fabrics blog post discussing the viability of using VXLAN and EVPN in times when the equipment lead times can exceed 12 months. Here it is:

Interesting article Ivan. Another major problem I see for EPVN, is the incompatibility between vendors, even though it is an open standard. With today’s crazy switch delivery times, we want a multi-vendor solution like BGP or LACP, but EVPN (due to vendors) isn’t ready for a multi-vendor production network fabric.

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EVPN/VXLAN or Bridged Data Center Fabric?

An attendee in the Building Next-Generation Data Center online course sent me an interesting dilemma:

Some customers don’t like EVPN because of complexity (it is required knowledge BGP, symmetric/asymmetric IRB, ARP suppression, VRF, RT/RD, etc). They agree, that EVPN gives more stability and broadcast traffic optimization, but still, it will not save DC from broadcast storms, because protections methods are the same for both solutions (minimize L2 segments, storm-control).

We’ll deal with the unnecessary EVPN-induced complexity some other time, today let’s start with a few intro-level details.

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netlab Release 1.3.1: BGP local-as, FRR and Cumulus Data Plane Enhancements

netlab release 1.3.1 contains major additions to FRR and Cumulus Linux, and new BGP features:

Here are some of the other goodies included in this release:

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The Basics of Network Address Translation (NAT)

The last video in the 2-hour-long Network Addressing part of How Networks Really Work discusses Network Address Translation.

After watching it, you might want to spend some extra quality time (with a bit of soap opera vibe) enjoying the recent Dual ISP deployment operational issues and uncertainties thread on the v6ops mailing list with a “surprising” result: NPTv6 or NAT66 is the least horrible way to do it.

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Multi-Cloud: Myths and Reality

I keep hearing numerous variations of the following argument from people believing in the unlimited powers of multi-cloud1 (deploying your workloads in multiple public cloud providers):

We don’t install all our servers in the same DC. But would you trust one Cloud Server Provider with all your applications? That’s why you should use multi-cloud.

I’ve been hearing similar arguments for at least 30 years, including:

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VLAN Interfaces and Subinterfaces

Early bridges implemented a single bridging domain across all ports. Within a few years, we got multiple bridging domains within a single device (including bridging implementation in Cisco IOS). The capability to have multiple bridging domains stretched across several devices was still missing… until the modern-day Pandora opened the VLAN box and forever swamped us in the complexities of large-scale bridging.

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Infrastructure-as-Code Sounds Scary

One of my readers preparing for public cloud deployment sent me an interesting observation:

I pushed to use infrastructure-as-code as we move to Azure, but I’m receiving a lot of pushback due to most of the involved parties not having any experience with code. Management is scared to use any kind of “homegrown” tools that only a few would understand. I feel like I’m stuck deploying and managing the environment manually.

It looks like a bad case of suboptimal terminology for this particular audience. For whatever reason, some infrastructure engineers prefer to stay as far away from programming as possible1, and infrastructure-as-code sounds like programming to them.

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