> For the complete documentation index, see [llms.txt](https://archive-docs.klaytn.foundation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://archive-docs.klaytn.foundation/content/klaytn/design/kni.md).

# KNI

**KNI (Klaytn Network Identifier)** is a URL scheme to identify a Klaytn node. Its syntax is shown below:

```
kni://<nodeID>@<hostname>:<port>?subport=<subport>&discport=<discport>
```

![KNI scheme](/files/M1KxkdMrpxoJx7Kzd5j6)

**nodeID** is a 512-bit public key corresponding to the node's private key. It is used to verify communication with peers on p2p network.

**hostname** describes the address of a node, located between `@` and `:`. The address format can be one of the following:

* IPv4 dotted decimal (`192.0.2.1`)
* IPv6 (`[2001:db8::68]`)
* IPv4-mapped IPv6 (`[2001:db8:3c4d:15::abcd:ef12]`)
* Domain name (`your.node.com`)

**port** is used to make connections with peer nodes through TCP. In Klaytn, the default `port` is `32323` and the default `subport` is `32324`. Note that the default `subport` is configured as `port + 1` in `kend.conf`. Depending on the number of TCP listening ports, Klaytn offers two [types of connections](/content/klaytn/design/multiport.md).

**discport** is used for checking if the known neighbors are reachable klaytn nodes and fetching their neighbors' addresses for new connections. Note that this is a UDP port. By default, the UDP port, or `discport`, uses the same port with the TCP port. If the node uses a different port for `discport`, it can be specified by the `discport` query parameter.

The following two URLs shows a KNI example of a node having IP address `10.0.0.1` and TCP listening port `32323` and `32324`. If `discport` is omitted, it is set to the UDP port of `32323`, same as the value of `port`.

```
kni://a979...163c@10.0.0.1:32323                 # either single-channel or multi-channel peer with omitted subport
kni://a979...163c@10.0.0.1:32323?subport=32324   # multi-channel peer
```

The next two shows KNI examples of nodes having `discport` of `30301`.

```
kni://a979...163c@10.0.0.1:32323?discport=30301                 # either single-channel or multi-channel peer with omitted subport
kni://a979...163c@10.0.0.1:32323?subport=32324&discport=30301   # multi-channel peer
```

If you want to know how to generate a KNI of a node, please refer to [Node Key & Node URI Creation](/content/installation-guide/deployment/core-cell/installation-guide/before-you-install.md#node-key-node-uri-creation). The KNI scheme is used in node discovery protocol, [setting `static-nodes.json` file](/content/installation-guide/deployment/core-cell/installation-guide/proxy-node-setup/configuration.md#install-static-nodes-json), [addPeer API](/content/dapp/json-rpc/api-references/admin.md#admin_addpeer), [bootnodes option](/content/operation-guide/configuration.md#properties) and etc.