net: allow selecting BIP152 high-bandwidth peers with `-addnode` #35940

pull w0xlt wants to merge 4 commits into bitcoin:master from w0xlt:feature/addnode-bip152-hb changing 8 files +189 −16

w0xlt commented at 5:57 AM on August 10, 2026: contributor
Bitcoin Core automatically selects up to three BIP152 high-bandwidth peers after they deliver useful blocks. This works for ordinary connections, but it cannot use topology information known by the operator.

For example, an operator may run nodes in multiple locations or maintain a stable, low-latency peering link and want that connection to announce compact blocks immediately and consistently, including after reconnects, instead of waiting for automatic selection.

This PR adds an opt-in suffix:
```
-addnode=<host>[:port]=bip152-hb
```
A matching outbound peer receives the existing SENDCMPCT(1) request after the handshake. The policy is reapplied on reconnect and requires no new P2P protocol messages.

Configured peers are additional to the three automatically selected peers and are not included in automatic rotation. This intentionally allows explicit configuration to exceed BIP152’s current three-peer limit and may increase redundant bandwidth. If accepted, BIP152 can be updated separately.

The option is incompatible with -blocksonly. Untagged addnodes, inbound connections, and the addnode RPC retain their existing behavior; RPC support can be considered separately.

net, init: pass -addnode values to CConnman as AddedNodeParams

Build the AddedNodeParams records in init.cpp instead of passing raw
strings to CConnman, and move the added-node v2 transport decision out of
CConnman::Init() accordingly. This lets startup code attach per-added-node
settings in a follow-up commit.

No behavior change.

b1a6f73333

net: match outbound peers to BIP152 HB added-node policy

Match durable outbound peers against persistent added-node records without
carrying policy through connection creation. Snapshot tagged endpoints
under the added-node mutex, then compare exact destinations and numeric
services without name lookups.

This covers normal added-node connections, name-proxy destinations,
numeric aliases, and BIP324 reconnections while keeping DNS out of
connection initialization.

cd501f9b6b

net, init: configure BIP152 high bandwidth for added nodes

Recognize the exact =bip152-hb suffix on persistent -addnode entries and
classify matching durable outbound peers during peer initialization.

Use the existing SENDCMPCT sent at VERACK to request high-bandwidth
announcements, and keep configured peers outside the automatic
three-peer rotation list.

f6b7fb689c

doc: add release note for BIP152 high-bandwidth added nodes 8ebd31e84c
DrahtBot added the label P2P on Aug 10, 2026
DrahtBot commented at 5:57 AM on August 10, 2026: contributor


The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.



Code Coverage & Benchmarks

For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/35940.



Reviews

See the guideline and AI policy for information on the review process. A summary of reviews will appear here.



Conflicts

Reviewers, this pull request conflicts with the following ones:
- #35561 (net: move some CNodeState fields to Peer by Crypt-iQ)
If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

Contributors

w0xlt

DrahtBot

Labels

P2P

net: allow selecting BIP152 high-bandwidth peers with `-addnode` #35940

Code Coverage & Benchmarks

Reviews

Conflicts