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Port 6343 (sflow)

IANA assigns port 6343 to sflow: sFlow traffic monitoring.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
sflow TCP sFlow traffic monitoring Peter Phaal -
sflow UDP sFlow traffic monitoring Peter Phaal -

Registry dates for this port: registered 2003-06.

Check what is listening on port 6343

Linux: is anything listening on TCP 6343?
sudo ss -tlnp 'sport = :6343'
Linux: UDP 6343
sudo ss -ulnp 'sport = :6343'
Linux / macOS: which process owns the port
sudo lsof -nP -i :6343
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':6343 '
Windows (Command Prompt)
netstat -ano | findstr :6343
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 6343 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 6343
From Windows
Test-NetConnection HOST -Port 6343
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 6343

Block port 6343 in the firewall

ufw
sudo ufw deny 6343/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 6343 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 6343 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 6343' -Direction Inbound -Protocol TCP -LocalPort 6343 -Action Block
ufw
sudo ufw deny 6343/udp
iptables
sudo iptables -A INPUT -p udp --dport 6343 -j DROP
nftables
sudo nft add rule inet filter input udp dport 6343 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 6343' -Direction Inbound -Protocol UDP -LocalPort 6343 -Action Block

Related ports

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Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.