Category: Tags
EVPN
ChatGPT trying (and failing) to explain EVPN
What Is EVPN?
Before going into the technical details, let’s start with the basics: What is EVPN, how does it work, and where can you use it?
- What Is EVPN?
- EVPN: The Great Unifying Theory of VPN Control Planes?
- EVPN Is More than VPLS on Steroids
- BGP, EVPN, VXLAN, or SRv6?
- Multivendor EVPN Just Works
- Why Are We Using EVPN Instead of SPB or TRILL?
- VXLAN Broadcast Domain Size Limitations
- Active-Active Data Centers with VXLAN and EVPN
- Comparing EVPN with Flood-and-Learn Fabrics
- Studying EVPN to Prepare for a Job Interview
- Is Dynamic MAC Learning Better Than EVPN?
- Dataplane MAC Learning with EVPN
EVPN Designs
EVPN was designed to be used in an IBGP environment on top of an IGP. With the eruption of EBGP as better IGP hype, many vendors tried to adapt EVPN to an environment running EBGP instead of OSPF. We covered some of the typical EVPN designs in these blog posts:
- BGP in EVPN-Based Data Center Fabrics
- Using EVPN in Very Small Data Center Fabrics
- Pragmatic EVPN Designs
- VXLAN Leaf-and-Spine Fabric
- IBGP Full Mesh Between Leaf Switches
- BGP Route Reflectors Considered Harmful
- Scaling IBGP with Route Reflectors
Other blog posts focus on various design details:
- BGP in EVPN-Based Data Center Fabrics (Updated)
- Scaling EVPN BGP Routing Designs
- Implications of Valley-Free Routing in Data Center Fabrics
- VXLAN and EVPN on Hypervisor Hosts
- When EVPN EBGP Session between Loopbacks Makes Sense
- BGP AS Numbers on MLAG Members
- EVPN/VXLAN or Bridged Data Center Fabric?
- Multi-Vendor EVPN Fabrics
- Layer-3 WAN Handoff (L3Out) in VXLAN/EVPN Fabrics
- VXLAN/EVPN Layer-3 Handoff (L3Out) on Arista EOS
Finally, several blog posts describe various EVPN VPN topologies:
- Simple EVPN/VXLAN Bridging
- Building Layer-3-Only EVPN Lab
- Layer-3-Only EVPN: Behind the Scenes
- Common Services VRF with EVPN Control Plane
EVPN Implementation Details
There are tons of tiny little things that can go wrong when you try to deploy EVPN. I documented them as I stumbled upon them:
- EVPN Route Target Considerations in EBGP Environment
- Using 4-Byte BGP AS Numbers With EVPN on Junos
- Dissecting IBGP+EBGP Junos Configuration
- Private VLANs With VXLAN
- VMware NSX Killed My EVPN Fabric
- EVPN Route Targets, Route Distinguishers, and VXLAN Network IDs
- EVPN Auto-Rd and Duplicate MAC Addresses
- Next-Hop and VTEP Reachability in EVPN Networks
- Duplicate ARP Replies with Anycast Gateways
- More Arista EOS BGP Route Reflector Woes
- Using EVPN/VXLAN with MLAG Clusters
- DHCP Relaying in EVPN VRFs
- Silent Hosts in EVPN Fabrics
- Repost: Campus-Wide Wireless Roaming with EVPN
- Using Multiple Transit VNIs per EVPN VRF
Beyond VXLAN
While EVPN is often used with VXLAN today, it was designed to work with the MPLS data plane, resulting in a few quirks:
- EVPN With MPLS Data Plane in Data Centers
- Q-in-Q Support in Multi-Site EVPN
- EVPN/MPLS Bridging Forwarding Model
- EVPN VLAN-Aware Bundle Service
- Does EVPN/VXLAN over SD-WAN Make Sense?
EVPN Rants
Some vendors’ marketing engineers (or Senior Directors) can’t stand anyone telling them their implementation might be suboptimal, going to great lengths to prove to themselves they’re right, and generating beautiful fodder for rants.
- Don’t Sugarcoat the Challenges You Have
- The EVPN Dilemma
- The EVPN/EBGP Saga Continues
- EVPN Control Plane in Infrastructure Cloud Networking
- EVPN/VXLAN Complexity
- On the Viability of EVPN
- Multi-Vendor EVPN Fabrics
- LISP vs EVPN: Mobility in Campus Networks
Videos
You can watch numerous videos from the EVPN Technical Deep Dive webinar without an ipSpace.net account:
- EVPN Multihoming Taxonomy and Overview
- EVPN Multihoming Deep Dive
- MLAG with EVPN
- vPC Fabric Peering with EVPN Multihoming
- Advantages and Drawbacks of EVPN-based Multihoming
What Others Wrote About EVPN
- EVPN in Data Center
- Arista EVPN-Based Automation Virtual Lab
- Switching to IP fabrics
- ARP Problems in EVPN
- EVPN/VXLAN with FRR on Linux Hosts
- Troubleshooting EVPN Control Plane
- Introduction of EVPN at DE-CIX
netlab
The netlab tool will help you be more proficient once you decide to drop GUI-based network simulators and build your labs using CLI and infrastructure-as-code principles.
You can also use netlab (potentially together with GitHub Codespaces) to build online, easy-to-consume, hands-on training solutions. I used that approach to build the BGP labs.
AI
Artificial Intelligence (AI) and Machine Learning (ML) are the next big hype in networking following Software-Defined Everything and Intent-Based Everything. Like with the previous hype bubbles it’s worth figuring out
- How much of the hype is real (TL&DR: not much)?
- Whether the technology is ready to be used in production networks (TL&DR: some of it)
- How you could use the technology to make your life easier
How Real Is It?
Like with the previous hype tsunamis I’ll do my best to help you figure out the answers to the above questions with a hefty dose of skepticism and snark1, starting with:
I also decided to “kick the tires” and document my (often less-than-stellar) experience with the most-overhyped products:
- Real-Life Not-Exactly-Networking AI Use Case
- ChatGPT on BGP Routing Security
- Kicking the Tires of GitHub Copilot
- Building a Small Network with ChatGPT
- ChatGPT Explaining the Need for iSCSI CRC
- Source IP Address in Multicast Packets
AI/ML in Networking: The Good, the Bad and the Ugly
Javier Antich created a wonderful AI/ML in Networking in 2021. If you know nothing about AI/ML and wonder whether you should care about it, you MUST watch these videos from his webinar:
- Introduction to AI/ML Hype
- Machine Learning 101
- Machine Learning Techniques
- Use Cases for AI/ML in Networking
- The Long Tail of AI/ML Problems
- Ugly Challenges of Using AI/ML in Networking
- Language Models in AI/ML Landscape
- Language Model Basics
In 2023, Javier published a book covering the same set of topics in way more details. I would highly recommend you read it if you want to know more.
What Others Are Saying
I keep collecting interesting articles talking about AI in general and (lately) ChatGPT. I found these interesting enough to mention them in worth reading blog posts:
- MUST READ: ChatGPT Is Bullshit (2024)
- Machine Learning Explained (2020)
- AI Makes Animists of Us All (2022)
- The AI Illusion (2022)
- Collections: On ChatGPT (a Historian Perspective) (2023)
- Putting Large Language Models in Context (2023)
- The Dangers of Knowing Everything (2023)
- Building Trustworthy AI (2023)
- Cargo Cult AI (2023)
- Building Stuff with Large Language Models Is Hard (2023)
- Worth Reading: AI Does Not Help Programmers (2023)
- Eyes that glaze over. Eyes like saucers. Eyes that narrow. (2023)
- Networking for AI Workloads (2023)
- Looking Inside Large Language Models (2023)
- Where Are the Self-Driving Cars? (2023)
- AI Risks (2023)
- State-of-the-Art AI (2023)
- The AI Supply Paradox (2023)
- ChatGPT Does Not Summarize (2024)
- You Probably Don't Need AI (2024)
- GitHub Copilot Workspace Review (2024)
- AI Is Still a Delusion (2024)
- AI and Google’s Quarterly Results (2024)
These are not bad either:
- What Is ChatGPT Doing … and Why Does It Work?
- We Can’t Build a Hut to the Moon
- The Delusion at the Center of the A.I. Boom (aka AI Solutionism)
- ChatGPT and Chemistry
- Cal Newport on ChatGPT
- Ruby Development with ChatGPT
- ChatGPT Is Your New Intern
- Using ChatGPT as a Technical Writing Assistant
- Why OpenAI is the new AWS
- Overemployed Hustlers Exploit ChatGPT To Take On Even More Full-Time Jobs
Finally, a few real-life uses of large language models:
- An Exploration of Embeddings and Vector Databases
- How GPT and LLMs will affect documentation
- I Built an AWS Well-Architected Chatbot with ChatGPT
- Building Boba AI – how to build a custom user interface in front of a large language model.
- Using Langchain to interact with ChatGPT
Blog Posts I Forgot to Categorize
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Please don’t blame me for pointing out the ever-lasting validity of Sturgeon’s law. Contrary to what some people think, I’m not trying hard to pick up dismal examples of AI failures, I’m just good at looking in the wrong places. Also, I’m too old to be wearing rosy glasses and drinking Kool-Aid. ↩︎