What are the Ethereum 2.0 testnets?

Question

There are many different Ethereum 2.0 testnets, among them

• Medalla
• Spadina
• Zinken

What are the differences and what is their purpose?

Answer 1

Ethereum 2.0 testnets can be categorized in different stages of testing, varying in their complexity of operation.

0. semi-public devnets
1. single-client testnets
2. multi-client testnets
3. semi-public attacknets
4. post-launch testnets

semi-public devnets

While implementing the Ethereum 2.0 protocol and before announcing releases, the core client developers maintain their semi-public testnets to develop and test the protocol against.

The first documented devnets in late 2019 were:

• Lighthouse Testnet 0
• Nimbus Testnet 0
• Nimbus Testnet 1
• Lighthouse Testnet 2

single-client testnets

Once the clients reach a certain maturity, clients release their testnets to the public and invite community members to participate in consensus by providing validators.

The first single-client testnets in early 2020 were:

• Lighthouse Testnet 5
• Prysm Sapphire
• Prysm Topaz
• Prysm Onyx

multi-client testnets

At some point, the different clients had to start to work together with regards to networking and consensus. The most critical part about multi-client testnets was ensuring that all clients properly implement the Eth2 specification.

The first multi-client testnets were:

• Schlesi Testnet: Lighthouse and Teku
• Witti Testnet: Prysm, Lighthouse, and Teku
• Altona Testnet: Prysm, Lighthouse, Teku, and Nimbus
• Medalla Testnet: Prysm, Lighthouse, Teku, Nimbus, and Lodestar
• Spadina Testnet: "dress rehearsal" testnet to practice mainnet launch procedure
• Zinken Testnet: "dress rehearsal" testnet to practice mainnet launch procedure

semi-public attacknets

Attack-networks are specially prepared testnets that should encourage testers to try breaking them.

Multiple tiers of bounties were available for breaking the following networks:

• Single-client beta-0 attacknets
• Multi-client beta-1 attacknets

post-launch testnets

Once the Ethereum 2.0 beacon chain launches, it's expected to see a new generation of testnets that serve the purpose to assist developers implementing applications and testing potential protocol upgrades.

other testing efforts

In addition to testnets, the following notable testing efforts have been conducted:

• Multinet: a collection of scripts to simulate multi-client testnets
• Beacon Fuzz: differential fuzzing framework for the Ethereum 2.0 clients