HTTPfy

Port 18635 (rds-ip)

IANA assigns port 18635 to rds-ip: Reliable Datagram Service over IP.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
rds-ip TCP Reliable Datagram Service over IP Andy Grover -
rds-ip UDP Reliable Datagram Service over IP Andy Grover -

Registry dates for this port: registered 2009-05-20.

Check what is listening on port 18635

Linux: is anything listening on TCP 18635?
sudo ss -tlnp 'sport = :18635'
Linux: UDP 18635
sudo ss -ulnp 'sport = :18635'
Linux / macOS: which process owns the port
sudo lsof -nP -i :18635
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':18635 '
Windows (Command Prompt)
netstat -ano | findstr :18635
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 18635 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 18635
From Windows
Test-NetConnection HOST -Port 18635
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 18635

Block port 18635 in the firewall

ufw
sudo ufw deny 18635/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 18635 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 18635 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 18635' -Direction Inbound -Protocol TCP -LocalPort 18635 -Action Block
ufw
sudo ufw deny 18635/udp
iptables
sudo iptables -A INPUT -p udp --dport 18635 -j DROP
nftables
sudo nft add rule inet filter input udp dport 18635 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 18635' -Direction Inbound -Protocol UDP -LocalPort 18635 -Action Block

Related ports

18516heythings18634rds-ib18668vdmmesh, vdmmesh-disc18769ique

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