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Port 222 (rsh-spx)

IANA assigns port 222 to rsh-spx: Berkeley rshd with SPX auth.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
rsh-spx TCP Berkeley rshd with SPX auth - -
rsh-spx UDP Berkeley rshd with SPX auth - -

Check what is listening on port 222

Linux: is anything listening on TCP 222?
sudo ss -tlnp 'sport = :222'
Linux: UDP 222
sudo ss -ulnp 'sport = :222'
Linux / macOS: which process owns the port
sudo lsof -nP -i :222
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':222 '
Windows (Command Prompt)
netstat -ano | findstr :222
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 222 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 222
From Windows
Test-NetConnection HOST -Port 222
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 222

Block port 222 in the firewall

ufw
sudo ufw deny 222/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 222 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 222 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 222' -Direction Inbound -Protocol TCP -LocalPort 222 -Action Block
ufw
sudo ufw deny 222/udp
iptables
sudo iptables -A INPUT -p udp --dport 222 -j DROP
nftables
sudo nft add rule inet filter input udp dport 222 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 222' -Direction Inbound -Protocol UDP -LocalPort 222 -Action Block

Related ports

220imap3221fln-spx223cdc224masqdialer

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