ZIP: 255
Title: Deployment of the NU6.1 Network Upgrade
Owners: Daira-Emma Hopwood <daira-emma@electriccoin.co>
Credits: Arya
Status: Draft
Category: Consensus / Network
Created: 2025-05-06
License: MIT
Discussions-To: <https://github.com/zcash/zips/issues/1011>
The key word “MUST” in this document is to be interpreted as described in BCP 14 1 when, and only when, it appears in all capitals.
The term “network upgrade” in this document is to be interpreted as described in ZIP 200. 2
The character § is used when referring to sections of the Zcash Protocol Specification. 3
The terms “Mainnet” and “Testnet” are to be interpreted as described in § 3.12 ‘Mainnet and Testnet’. 4
This proposal defines the deployment of the NU6.1 network upgrade.
The primary sources of information about NU6.1 consensus protocol changes are:
The network handshake and peer management mechanisms defined in ZIP 201 5 also apply to this upgrade.
The following network upgrade constants 2 are defined for the NU6.1 upgrade:
0x4DEC4DF0170130170140For each network (Testnet and Mainnet), nodes compatible with NU6.1 activation on that network MUST advertise a network protocol version that is greater than or equal to the MIN_NETWORK_PROTOCOL_VERSION (NU6.1) for that activation.
Prior to the network upgrade activating on each network, NU6.1 and pre-NU6.1 nodes are compatible and can connect to each other. However, NU6.1 nodes will have a preference for connecting to other NU6.1 nodes, so pre-NU6.1 nodes will gradually be disconnected in the run up to activation.
Once the network upgrades, even though pre-NU6.1 nodes can still accept the numerically larger protocol version used by NU6.1 as being valid, NU6.1 nodes will always disconnect peers using lower protocol versions.