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Port 181 (unify)

IANA assigns port 181 to unify: Unify.

Well-known (system) port, 0-1023 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
unify TCP Unify Daegis Inc -
unify UDP Unify Daegis Inc -

Registry dates for this port: last modified 2012-07-31.

Check what is listening on port 181

Linux: is anything listening on TCP 181?
sudo ss -tlnp 'sport = :181'
Linux: UDP 181
sudo ss -ulnp 'sport = :181'
Linux / macOS: which process owns the port
sudo lsof -nP -i :181
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':181 '
Windows (Command Prompt)
netstat -ano | findstr :181
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 181 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 181
From Windows
Test-NetConnection HOST -Port 181
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 181

Block port 181 in the firewall

ufw
sudo ufw deny 181/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 181 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 181 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 181' -Direction Inbound -Protocol TCP -LocalPort 181 -Action Block
ufw
sudo ufw deny 181/udp
iptables
sudo iptables -A INPUT -p udp --dport 181 -j DROP
nftables
sudo nft add rule inet filter input udp dport 181 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 181' -Direction Inbound -Protocol UDP -LocalPort 181 -Action Block

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179BGP180ris182audit183ocbinder

All port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.