4.3 KiB
Ethereum Merge networking specification
This document contains the networking specification for Ethereum 2.0 clients added during the Merge deployment.
The specification of these changes continues in the same format as the network specifications of previous upgrades, and assumes them as pre-requisite. This document should be viewed as additive to the documents from Phase 0 and from Altair and will be referred to as the "Phase 0 document" and "Altair document" respectively, hereafter. Readers should understand the Phase 0 and Altair documents and use them as a basis to understand the changes outlined in this document.
Table of contents
Warning
This document is currently illustrative for early Merge testnets and some parts are subject to change. Refer to the note in the validator guide for further details.
Modifications in the Merge
The gossip domain: gossipsub
Some gossip meshes are upgraded in the Merge to support upgraded types.
Topics and messages
Topics follow the same specification as in prior upgrades. All topics remain stable except the beacon block topic which is updated with the modified type.
The specification around the creation, validation, and dissemination of messages has not changed from the Phase 0 and Altair documents.
The derivation of the message-id remains stable.
The new topics along with the type of the data field of a gossipsub message are given in this table:
| Name | Message Type |
|---|---|
beacon_block |
SignedBeaconBlock (modified) |
Note that the ForkDigestValue path segment of the topic separates the old and the new beacon_block topics.
Global topics
The Merge changes the type of the global beacon block topic.
beacon_block
The existing specification for this topic does not change from prior upgrades,
but the type of the payload does change to the (modified) SignedBeaconBlock found in the Merge.
This type changes due to the addition of execution_payload to the inner BeaconBlockBody.
See the Merge state transition document for further details.
Transitioning the gossip
See gossip transition details found in the Altair document for details on how to handle transitioning gossip topics for the Merge.
The Req/Resp domain
Messages
BeaconBlocksByRange v2
Protocol ID: /eth2/beacon_chain/req/beacon_blocks_by_range/2/
Request and Response remain unchanged.
The Merge fork-digest is introduced to the context enum to specify the Merge block type.
Per context = compute_fork_digest(fork_version, genesis_validators_root):
fork_version |
Chunk SSZ type |
|---|---|
GENESIS_FORK_VERSION |
phase0.SignedBeaconBlock |
ALTAIR_FORK_VERSION |
altair.SignedBeaconBlock |
MERGE_FORK_VERSION |
merge.SignedBeaconBlock |
BeaconBlocksByRoot v2
Protocol ID: /eth2/beacon_chain/req/beacon_blocks_by_root/2/
Request and Response remain unchanged.
The Merge fork-digest is introduced to the context enum to specify the Merge block type.
Per context = compute_fork_digest(fork_version, genesis_validators_root):
fork_version |
Chunk SSZ type |
|---|---|
GENESIS_FORK_VERSION |
phase0.SignedBeaconBlock |
ALTAIR_FORK_VERSION |
altair.SignedBeaconBlock |
MERGE_FORK_VERSION |
merge.SignedBeaconBlock |