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Port 432 (iasd)

IANA assigns port 432 to iasd: IASD.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
iasd TCP IASD Nir Baroz -
iasd UDP IASD Nir Baroz -

Check what is listening on port 432

Linux: is anything listening on TCP 432?
sudo ss -tlnp 'sport = :432'
Linux: UDP 432
sudo ss -ulnp 'sport = :432'
Linux / macOS: which process owns the port
sudo lsof -nP -i :432
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':432 '
Windows (Command Prompt)
netstat -ano | findstr :432
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 432 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 432
From Windows
Test-NetConnection HOST -Port 432
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 432

Block port 432 in the firewall

ufw
sudo ufw deny 432/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 432 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 432 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 432' -Direction Inbound -Protocol TCP -LocalPort 432 -Action Block
ufw
sudo ufw deny 432/udp
iptables
sudo iptables -A INPUT -p udp --dport 432 -j DROP
nftables
sudo nft add rule inet filter input udp dport 432 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 432' -Direction Inbound -Protocol UDP -LocalPort 432 -Action Block

Related ports

430utmpsd431utmpcd433nnsp434mobileip-agent

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