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Port 498 (siam)

IANA assigns port 498 to siam.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
siam TCP siam Philippe Gilbert -
siam UDP siam Philippe Gilbert -

Check what is listening on port 498

Linux: is anything listening on TCP 498?
sudo ss -tlnp 'sport = :498'
Linux: UDP 498
sudo ss -ulnp 'sport = :498'
Linux / macOS: which process owns the port
sudo lsof -nP -i :498
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':498 '
Windows (Command Prompt)
netstat -ano | findstr :498
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 498 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 498
From Windows
Test-NetConnection HOST -Port 498
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 498

Block port 498 in the firewall

ufw
sudo ufw deny 498/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 498 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 498 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 498' -Direction Inbound -Protocol TCP -LocalPort 498 -Action Block
ufw
sudo ufw deny 498/udp
iptables
sudo iptables -A INPUT -p udp --dport 498 -j DROP
nftables
sudo nft add rule inet filter input udp dport 498 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 498' -Direction Inbound -Protocol UDP -LocalPort 498 -Action Block

Related ports

496pim-rp-disc497retrospect499iso-ill500IKE (IPsec)

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