Port 8181 (intermapper)

IANA assigns port 8181 to intermapper: Intermapper network management system.

Registered (user) port, 1024-49151 TCP

IANA assignment

Service nameProtoDescriptionAssigneeReference

intermapper TCP Intermapper network management system William Fisher -

Registry dates for this port: registered 2011-05-09.

Linux: is anything listening on TCP 8181?

sudo ss -tlnp 'sport = :8181'

Linux / macOS: which process owns the port

sudo lsof -nP -i :8181

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':8181 '

Windows (Command Prompt)

netstat -ano | findstr :8181

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 8181 -State Listen | Select LocalAddress,OwningProcess

From another machine

nc -vz -w 5 HOST 8181

From Windows

Test-NetConnection HOST -Port 8181

ufw

sudo ufw deny 8181/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 8181 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 8181 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 8181' -Direction Inbound -Protocol TCP -LocalPort 8181 -Action Block

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