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Port 9801 (sstp-2)

IANA assigns port 9801 to sstp-2: Sakura Script Transfer Protocol-2.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
sstp-2 TCP Sakura Script Transfer Protocol-2 Kouichi Takeda 2 -
sstp-2 UDP Sakura Script Transfer Protocol-2 Kouichi Takeda 2 -

Check what is listening on port 9801

Linux: is anything listening on TCP 9801?
sudo ss -tlnp 'sport = :9801'
Linux: UDP 9801
sudo ss -ulnp 'sport = :9801'
Linux / macOS: which process owns the port
sudo lsof -nP -i :9801
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':9801 '
Windows (Command Prompt)
netstat -ano | findstr :9801
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 9801 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 9801
From Windows
Test-NetConnection HOST -Port 9801
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 9801

Block port 9801 in the firewall

ufw
sudo ufw deny 9801/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 9801 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 9801 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 9801' -Direction Inbound -Protocol TCP -LocalPort 9801 -Action Block
ufw
sudo ufw deny 9801/udp
iptables
sudo iptables -A INPUT -p udp --dport 9801 -j DROP
nftables
sudo nft add rule inet filter input udp dport 9801 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 9801' -Direction Inbound -Protocol UDP -LocalPort 9801 -Action Block

Related ports

9762tungsten-http9800davsrc9802davsrcs9875sapv1

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