Port 8500 (HashiCorp Consul HTTP)

Consul HTTP API and UI. Consul also uses 8300-8302 (RPC, Serf) and 8600 (DNS).

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

What port 8500 is used for

Consul HTTP API and UI. Consul also uses 8300-8302 (RPC, Serf) and 8600 (DNS).

Security: should port 8500 be open?

Do not expose to the internet. Without ACLs, anyone reaching 8500 can register services with health-check scripts and run commands on agents. Enable ACLs with default deny and keep it internal.

IANA assignment

Service nameProtoDescriptionAssigneeReference

fmtp TCP Flight Message Transfer Protocol Eivan Cerasi -

fmtp UDP Flight Message Transfer Protocol Eivan Cerasi -

Registry dates for this port: registered 2003-12.

Check what is listening on port 8500

Linux: is anything listening on TCP 8500?

sudo ss -tlnp 'sport = :8500'

Linux / macOS: which process owns the port

sudo lsof -nP -i :8500

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':8500 '

Windows (Command Prompt)

netstat -ano | findstr :8500

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 8500 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine

nc -vz -w 5 HOST 8500

From Windows

Test-NetConnection HOST -Port 8500

Block port 8500 in the firewall

ufw

sudo ufw deny 8500/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 8500 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 8500 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 8500' -Direction Inbound -Protocol TCP -LocalPort 8500 -Action Block

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