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Port 3687 (simple-push)

IANA assigns port 3687 to simple-push.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
simple-push TCP simple-push - -
simple-push UDP simple-push - -

Check what is listening on port 3687

Linux: is anything listening on TCP 3687?
sudo ss -tlnp 'sport = :3687'
Linux: UDP 3687
sudo ss -ulnp 'sport = :3687'
Linux / macOS: which process owns the port
sudo lsof -nP -i :3687
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':3687 '
Windows (Command Prompt)
netstat -ano | findstr :3687
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3687 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 3687
From Windows
Test-NetConnection HOST -Port 3687
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 3687

Block port 3687 in the firewall

ufw
sudo ufw deny 3687/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 3687 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 3687 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 3687' -Direction Inbound -Protocol TCP -LocalPort 3687 -Action Block
ufw
sudo ufw deny 3687/udp
iptables
sudo iptables -A INPUT -p udp --dport 3687 -j DROP
nftables
sudo nft add rule inet filter input udp dport 3687 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 3687' -Direction Inbound -Protocol UDP -LocalPort 3687 -Action Block

Related ports

3685dsx-agent3686tnmpv23688simple-push-s3689daap

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