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Port 4837 (varadero-0)

IANA assigns port 4837 to varadero-0: Varadero-0.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
varadero-0 TCP Varadero-0 - -
varadero-0 UDP Varadero-0 - -

Check what is listening on port 4837

Linux: is anything listening on TCP 4837?
sudo ss -tlnp 'sport = :4837'
Linux: UDP 4837
sudo ss -ulnp 'sport = :4837'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4837
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':4837 '
Windows (Command Prompt)
netstat -ano | findstr :4837
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4837 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 4837
From Windows
Test-NetConnection HOST -Port 4837
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4837

Block port 4837 in the firewall

ufw
sudo ufw deny 4837/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 4837 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 4837 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 4837' -Direction Inbound -Protocol TCP -LocalPort 4837 -Action Block
ufw
sudo ufw deny 4837/udp
iptables
sudo iptables -A INPUT -p udp --dport 4837 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4837 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4837' -Direction Inbound -Protocol UDP -LocalPort 4837 -Action Block

Related ports

4804aja-ntv4-disc4827htcp4838varadero-14839varadero-2

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