Cryptocurrency products use the following TCP ports (not UDP):
- Bitcoin : 8333
- Bitcoin Testnet : 18333
- Litecoin: 9333
- Dash: 9999
- Dogecoin: 22556
- Ethereum: 30303
This port is only used for full nodes which do validations
of transactions and blocks for Internet clients,
but are not required for non-validating lightweight clients.
Full nodes are defined as:
full node is a program that fully validates transactions and blocks.
Almost all full nodes also help the network by accepting transactions
and blocks from other full nodes, validating those transactions and
blocks, and then relaying them to further full nodes.
Most full nodes also serve lightweight clients by allowing them to
transmit their transactions to the network and by notifying them when
a transaction affects their wallet. If not enough nodes perform this
function, clients won’t be able to connect through the peer-to-peer
network—they’ll have to use centralized services instead.
When Bitcoin Core starts, it establishes 8 outbound connections to
other full nodes so it can download the latest blocks and
transactions. If you just want to use your full node as a wallet, you
don’t need more than these 8 connections—but
if you want to support lightweight clients and other full nodes on the network, you must allow inbound connections.
Some products use
Universal Plug and Play (uPnP)
to automatically open this port in the router.
Most (but not all) routers do support it, otherwise manual configuration
of the router is required to open the port and
Port Forward
it to the computer on which the node is running.
The port can usually also be configured as another number for most of the
products by local configuration.
This requires using
Port Forwarding
on the router
to transmit the known external port to the locally configured one
on the computer.
References :