---
terms: ["Canonically-unique-host"]
summary: "A host that is canonically resolved to an address or set of addresses"
---

{% include disclaimer.html translated="no" translationOutdated="no" %}

### The Basics

A Canonically-unique host is a [FQDN](https://en.wikipedia.org/wiki/FQDN) that will canonically resolve to a designated address or set of addresses. Not to be confused with a @locally-unique-host.

### In-depth information

A Canonically-unique host is defined by remote authoritative sources; usually through [DNS](https://en.wikipedia.org/wiki/DNS). When resolving a peer's hostname, you will most likely use an external source for resolution unless you have the following implemented:

- a database file similar to a [hosts file](https://en.wikipedia.org/wiki/Hosts_(file))
- an internal-network resolver (which eventually pulls from external sources)

### Notes

- Monero primarily uses @canonically-unique-host resolution while I2P only uses @locally-unique-host resolution.
- I2P's and @Kovri's self-assigned top-level domain is currently `.i2p` and @Kovri intends to only process/use the `.i2p` [top-level domain](https://en.wikipedia.org/wiki/Top_level_domain)