Ropsten Merge Announcement

The Merge Countdown: Ropsten Testnet Takes Center Stage

The Ethereum community has been eagerly awaiting the transition to proof-of-stake (PoS), and the latest development brings us one step closer to this milestone. The Ropsten testnet, the oldest proof-of-work (PoW) testnet, is set to undergo the Merge, marking a significant testing phase before the Ethereum mainnet makes the switch.

Background: The Merge

After years of work, the Ethereum community is now entering the final testing stage for the transition to proof-of-stake. The Merge is a complex upgrade that will bring significant changes to the Ethereum network, including the switch from PoW to PoS. This transition will have a profound impact on the network's security, scalability, and usability.

Ropsten Testnet: The First to Merge

The Ropsten testnet has been chosen as the first testnet to undergo the Merge. This decision was made to ensure that the transition is thoroughly tested and validated before moving on to other testnets. The Ropsten testnet was launched on May 30, 2022, with a new Beacon Chain to provide consensus to the network.

Upgrade Information: Timing and Process

The Merge is a two-step process. The first step involves a network upgrade on the consensus layer, triggered by a slot height. This is followed by the execution layer's transition from PoW to PoS, triggered by a specific Total Difficulty threshold, called the Terminal Total Difficulty (TTD).

On June 2, 2022, at slot 24000, the Bellatrix upgrade will prepare the Ropsten Beacon Chain for The Merge. At that point, CL clients will begin listening for a TTD value to be hit on the proof-of-work chain. Once the Bellatrix upgrade has happened on the Beacon Chain, a new TTD value will be chosen and announced. Users will then need to configure their node with this new value.

Client Releases and Compatibility

The following client releases support The Merge on the Ropsten testnet:

• Consensus Layer:
  • Lighthouse (Baby Wizard 2.3.0)
  • Lodestar (v0.37.0)
  • Prysm (v2.1.3-rc.2)
  • Nimbus (v22.5.2)
  • Teku (v22.5.2)
• Execution Layer:
  • Besu (v22.4.2)
  • Erigon (v2022.06.01-alpha)
  • go-ethereum (geth) (Sharblu v1.10.18)

Upgrade Specifications and APIs

The consensus-critical changes for The Merge are specified in two places:

• The consensus layer changes, under the bellatrix directory of the consensus-specs repository
• The execution layer changes, under the Paris spec in the execution-specs repository

In addition to these, two other specifications cover how the consensus and execution layer clients interact:

• The Engine API, specified in the execution-apis repository, is used for communication between the consensus and execution layers
• Optimistic Sync, specified in the sync folder of the consensus-specs repository, is used by the consensus layer to import blocks as the execution layer client is syncing and to provide a partial view of the head of the chain from the former to the latter

FAQ and Next Steps

• As a node operator, you should ensure that your clients are compatible with the new TTD value and configure your node accordingly.
• As a staker, you should ensure that your validators are paired with an execution layer client and that you have set the fee recipient as part of your validator client configurations.
• As an application or tooling developer, you should ensure that your product works as expected through the proof-of-stake transition and in a post-merge context.
• As an Ethereum user or Ether holder, there is no need to take any action.
• As a miner, you should be aware that mining will no longer be possible on the network after the Merge.
• As a validator, you cannot withdraw your stake yet, but withdrawals will likely be introduced in the first upgrade after The Merge.

Conclusion

The Merge on the Ropsten testnet marks a significant milestone in the transition to proof-of-stake. This testing phase will help ensure that the transition is thoroughly validated and that the Ethereum network is ready for the switch. The community should continue to monitor the progress and be prepared for the next steps in the process.

Source: https://blog.ethereum.org/en/2022/05/30/ropsten-merge-announcement