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Port 1644 (saiseh)

IANA assigns port 1644 to saiseh: Satellite-data Acquisition System 4.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
saiseh TCP Satellite-data Acquisition System 4 Bill Taylor -
saiseh UDP Satellite-data Acquisition System 4 Bill Taylor -

Check what is listening on port 1644

Linux: is anything listening on TCP 1644?
sudo ss -tlnp 'sport = :1644'
Linux: UDP 1644
sudo ss -ulnp 'sport = :1644'
Linux / macOS: which process owns the port
sudo lsof -nP -i :1644
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':1644 '
Windows (Command Prompt)
netstat -ano | findstr :1644
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 1644 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 1644
From Windows
Test-NetConnection HOST -Port 1644
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 1644

Block port 1644 in the firewall

ufw
sudo ufw deny 1644/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 1644 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 1644 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 1644' -Direction Inbound -Protocol TCP -LocalPort 1644 -Action Block
ufw
sudo ufw deny 1644/udp
iptables
sudo iptables -A INPUT -p udp --dport 1644 -j DROP
nftables
sudo nft add rule inet filter input udp dport 1644 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 1644' -Direction Inbound -Protocol UDP -LocalPort 1644 -Action Block

Related ports

1642isis-am1643isis-ambc1645sightline1646sa-msg-port

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