> For the complete documentation index, see [llms.txt](https://docs.mazze.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.mazze.io/architecture/networking.md).

# Networking

The `network` crate implements the P2P transport, discovery, and peer management used by sync and block propagation.

## Core services

* `NetworkService` manages sessions and protocol handlers.
* Discovery maintains a node table and periodically refreshes peers.
* Handshake and session layers enforce protocol compatibility.

## Configuration highlights

`NetworkConfiguration` includes:

* Listen/public addresses and UDP port.
* Bootnodes and reserved nodes.
* Peer limits and handshake limits.
* NAT and discovery settings.
* Throttling and IP filter controls.

## Node typing and tagging

Peers advertise `node_type` tags (archive/full) to bias requests during sync, and the sync layer can choose preferred node types for block retrieval.

## Shielded transactions and Dandelion++

Shielded transactions are relayed in their own message, `ShieldedTransactions` (`0x25`), sent only while the shielded lane is active. They are routed with Dandelion++:

* **Stem:** forwarded to one peer at a time, the node's current stem successor (redrawn every 10 minutes).
* **Fluff:** at each hop, with probability 0.1, switched to an ordinary broadcast.
* **Embargo:** a node that relays a stem transaction broadcasts it itself if it has not seen it broadcast within 30 to 60 seconds.

The node a transaction came from is then not the first to broadcast it. See [The shielded lane](/shielded-space/shielded-lane.md#relay-dandelion).

## Handshake

The cryptographic handshake cannot be bypassed in release builds. The `BYPASS_CRYPTOGRAPHY` switch exists only in test builds, and a release build logs an error if anything tries to flip it.

## Key source files

* `crates/network/src/lib.rs`
* `crates/network/src/service.rs`
* `crates/network/src/discovery.rs`
* `crates/mazzecore/core/src/sync/message/status.rs`
* `crates/mazzecore/core/src/sync/dandelion.rs`
* `crates/mazzecore/core/src/sync/message/shielded_transactions.rs`