- Sepolia testnet to undergo post-merger execution layer (EL) upgrade in the block 1735371expected on August 17, 2022
- The update will cause EL clients on the network to be disconnected from peers that have not transitioned to proof-of-stake. It does not add additional functionality beyond this.
- Sepolia node operators must update their execution layer client before blocking 1735371.
- A similar upgrade is expected on Goerli and the Ethereum mainnet once these networks have transitioned to proof-of-stake.
Bottom
To maintain a healthy peer list, nodes in the Ethereum runtime layer will automatically disconnect peers that do not have the same update sequence as them. On the Ethereum mainnet, this means checking if a peer upgraded to border thawing in block 200,000, then Farm in block 1,150,000, and so on until the last update, Glacier GrayWhat happened in block 15,050,000. EIP-2124 specifies how this is handled. In typical network updates, which are triggered by a block height, this happens automatically when nodes use the block height of upcoming updates to filter peers.
For The Merge, this was not possible because the update was triggered by a absolute difficulty value instead of a block number. The rationale for this choice is explained in EIP-3675:
The use of a predefined block number for the hard fork is not safe in this context because the choice of the PoS fork takes precedence during the transition.
An attacker can use a minority of hash power to build a malicious chain fork that satisfies the block height requirement. Then, the first PoS block can be maliciously proposed on top of the PoW block of this adversarial fork, becoming the head and undermining the security of the transition.
To protect the network from this attack scenario, the difficulty accumulated by the chain (total difficulty) is used to trigger the update.
To minimize changes to the protocol during its most complex upgrade since release, The Merge was designed to exclude support for EIP-2124. This means that an additional update now needs to be done to add this. It is important to note that the only change introduced as part of this update is to specify a block number that nodes can use to identify peers that have gone through The Merge. No other functionality is introduced or deprecated as part of this update.
update information
Synchronization
This update will happen in Sepolia on the block 1735371expected on August 17, 2022.
Please note that a similar update will be announced for Goerli and mainnet after these networks have transitioned to proof of stake.
Ropsten’s Will not be updated as it is now considered obsolete, along with Rinkeby and Kiln. Watch this post for more details on your deactivation schedule.
customer launches
Only runtime layer clients need to be updated for this update. Node operators can continue to run their current consensus layer client version on Sepolia during the transition.
Please note that the client versions used for the Goerli/Prater merge all support from this update into Sepolia. In other words, if you already downloaded a version for the Goerli/Prater merger, you can use that same version in Sepolia for this update.
execution layer
upgrade specs
The specification of this change is tracked as part of the Paris specifications, under FORK NEXT Update section.
Frequently asked questions
As a node operator, what should I do?
You must update your execution layer client to one of the versions listed above by August 16, 2022. You do not need to update your consensus layer client.
As a staker, what should I do?
The validator set to Sepolia has permission. If you are part of the current Sepolia validators, you must update your runtime client to one of the versions listed above by August 16, 2022.
If it’s not part of the current set of Sepolia validators, you don’t need to do anything at this point.
Goerli/Prater and mainnet validators will need to follow the same steps when this update is announced on those networks.
As an application or tool developer, what should I do?
Nothing, unless you’re also running a node. If so, please upgrade your runtime client to one of the versions listed above by August 16, 2022.
As an Ethereum user or Ether holder, do I need to do anything?
No. The Ethereum mainnet is not affected by this update. Even when this update is applied to the main network, no action is required.
thanks to justin chrono for the original cover image and Tomo Saito for the edits.
