HTTPfy

Port 15363 (3link)

IANA assigns port 15363 to 3link: 3Link Negotiation.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
3link TCP 3Link Negotiation Brant Thomsen -
3link UDP 3Link Negotiation Brant Thomsen -

Registry dates for this port: registered 2003-01.

Check what is listening on port 15363

Linux: is anything listening on TCP 15363?
sudo ss -tlnp 'sport = :15363'
Linux: UDP 15363
sudo ss -ulnp 'sport = :15363'
Linux / macOS: which process owns the port
sudo lsof -nP -i :15363
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':15363 '
Windows (Command Prompt)
netstat -ano | findstr :15363
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 15363 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 15363
From Windows
Test-NetConnection HOST -Port 15363
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 15363

Block port 15363 in the firewall

ufw
sudo ufw deny 15363/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 15363 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 15363 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 15363' -Direction Inbound -Protocol TCP -LocalPort 15363 -Action Block
ufw
sudo ufw deny 15363/udp
iptables
sudo iptables -A INPUT -p udp --dport 15363 -j DROP
nftables
sudo nft add rule inet filter input udp dport 15363 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 15363' -Direction Inbound -Protocol UDP -LocalPort 15363 -Action Block

Related ports

15118v2g-secc15345xpilot15555cisco-snat15660bex-xr

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