Port 8545 (Ethereum JSON-RPC)

JSON-RPC HTTP API of Ethereum nodes (Geth, Hardhat, Anvil, Ganache).

Registered (user) port, 1024-49151 TCP Peer-to-peer Do not expose to the internet

What port 8545 is used for

JSON-RPC HTTP API of Ethereum nodes (Geth, Hardhat, Anvil, Ganache).

Security: should port 8545 be open?

Do not expose to the internet. Exposed nodes with unlocked accounts were drained by scanners; bind to localhost and never unlock accounts on an RPC-exposed node.

IANA assignment

Port 8545 is in the registered range and has no IANA assignment. The usage above is unofficial but widespread.

Check what is listening on port 8545

Linux: is anything listening on TCP 8545?

sudo ss -tlnp 'sport = :8545'

Linux / macOS: which process owns the port

sudo lsof -nP -i :8545

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':8545 '

Windows (Command Prompt)

netstat -ano | findstr :8545

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 8545 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine

nc -vz -w 5 HOST 8545

From Windows

Test-NetConnection HOST -Port 8545

Block port 8545 in the firewall

ufw

sudo ufw deny 8545/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 8545 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 8545 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 8545' -Direction Inbound -Protocol TCP -LocalPort 8545 -Action Block

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Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.