# `bitcoin-network`
---
The `bitcoin-network` crate is a direct
translation of the Bitcoin codebase from C++ to
Rust, and is one of the subcomponents of the
Bitcoin system. This crate provides a set of data
structures and functions related to network
communication and message propagation within the
Bitcoin network.
The crate includes structures such as `NetAddr`,
which represents a network address used to
communicate with other Bitcoin nodes, and
`Network`, which represents the Bitcoin network
protocol. The `ZeroSpan` type is used for
zero-length spans, and `Reachability` represents
the reachability of a Bitcoin node.
The functions provided by the crate include
methods to check the validity and properties of
network addresses, serialize and unserialize
network data, and get various network-related
information. The crate also includes functions to
calculate network-related mathematical properties,
such as the netmask bits of an IP address.
Overall, the `bitcoin-network` crate is a critical
component of the Bitcoin system, providing the
necessary functionality to communicate and
propagate messages across the Bitcoin network.
38> thanks -- could you tell me about NetAddr?
NetAddr is a Rust structure used in the Bitcoin
network to represent network addresses. It
includes an IP address and a port number, as well
as other information such as the network version
and the reachability of the address.
In Bitcoin, network addresses are used to maintain
a peer-to-peer network of nodes that communicate
with each other to transmit transactions and
blocks across the network. Each node in the
network maintains a list of known network
addresses to other nodes, which it can use to
establish new connections and maintain existing
ones.
NetAddr provides a convenient way to represent
these network addresses in Rust code, allowing for
easy serialization and deserialization of network
messages that contain network addresses.
The structure includes a number of methods to
manipulate and query the properties of network
addresses, such as `is_reachable()`, which checks
if the address is currently reachable on the
network, and `to_string()`, which returns a string
representation of the address.
Overall, NetAddr is a useful tool for managing and
manipulating network addresses in the context of
the Bitcoin network.