Port 8890 (ddi-tcp-3, ddi-udp-3)

IANA assigns port 8890 to ddi-tcp-3, ddi-udp-3: Desktop Data TCP 2.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference

ddi-tcp-3 TCP Desktop Data TCP 2 Fred Yao -

ddi-udp-3 UDP NewsEDGE client broadcast Fred Yao -

Linux: is anything listening on TCP 8890?

sudo ss -tlnp 'sport = :8890'

Linux: UDP 8890

sudo ss -ulnp 'sport = :8890'

Linux / macOS: which process owns the port

sudo lsof -nP -i :8890

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':8890 '

Windows (Command Prompt)

netstat -ano | findstr :8890

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 8890 -State Listen | Select LocalAddress,OwningProcess

From another machine

nc -vz -w 5 HOST 8890

From Windows

Test-NetConnection HOST -Port 8890

UDP probe (no reply does not prove it is closed)

nc -vzu -w 5 HOST 8890

ufw

sudo ufw deny 8890/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 8890 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 8890 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 8890' -Direction Inbound -Protocol TCP -LocalPort 8890 -Action Block

ufw

sudo ufw deny 8890/udp

iptables

sudo iptables -A INPUT -p udp --dport 8890 -j DROP

nftables

sudo nft add rule inet filter input udp dport 8890 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block UDP 8890' -Direction Inbound -Protocol UDP -LocalPort 8890 -Action Block

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Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.