Motivation

In #1823 we added initial support for NU5 to zebra. Right now this support is incomplete since we have not finished drafting the zip for the next network upgrade, so we don't yet know things like the activation height or the precise consensus rule changes that will be made in NU5.
-Track all NU5 epics

Solution

Once we've finalized the proposal for NU5 we need to follow up on the initial support to replace various todo's in the code and replace them with the specified logic.

Note: NU5 also contains other ZIPs, see #1598 and ZIP-252.

Testnet: ZIP-252

Zebra:

• Set the NU5 testnet activation height, network protocol version, and consensus branch ID #2793
• Set the CURRENT_NETWORK_PROTOCOL_VERSION to 170_014 for NU5 testnet #2794
• Update the NU5 testnet Zebra version in ZIP-252 #2795
• Terminate all Foundation Zcash instances running pre-NU5 testnet versions #2798

DNS Seeders:

• Change the max network protocol version in the DNS seeder to 170_014 for NU5 testnet #2796
  • Change the max network protocol version in the DNS seeder to 170_015 for NU5 testnet #2808
• Re-deploy the foundation's DNS seeders for NU5 testnet #2797

The DNS seeders don't check the activation height. So it's ok to increase the maximum version a few weeks early.

Mainnet: ZIP-252

Zebra mainnet:

• Set the NU5 mainnet activation height and network protocol version #4115
• Tag Zebra NU5 mainnet version #3948
• Set the minimum network protocol version to 170_100 after NU5 mainnet activation #4117 (after activation)

Zebra testnet:

• Set the minimum network protocol version to 170_050 for NU5 testnet #4116 (after activation)

DNS Seeders:

• Increment the maximum network protocol version accepted by the foundation's DNS seeders to 170_017
• Re-deploy the foundation's DNS seeders
  • Check that the mainnet seeder is returning new peers
  • Check that the testnet seeder continues to return new peers