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Port 5300 (hacl-hb)

IANA assigns port 5300 to hacl-hb: HA cluster heartbeat.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
hacl-hb TCP HA cluster heartbeat Eric Soderberg 2, Edward Yim -
hacl-hb UDP HA cluster heartbeat Eric Soderberg 2, Edward Yim -

Check what is listening on port 5300

Linux: is anything listening on TCP 5300?
sudo ss -tlnp 'sport = :5300'
Linux: UDP 5300
sudo ss -ulnp 'sport = :5300'
Linux / macOS: which process owns the port
sudo lsof -nP -i :5300
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':5300 '
Windows (Command Prompt)
netstat -ano | findstr :5300
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 5300 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 5300
From Windows
Test-NetConnection HOST -Port 5300
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 5300

Block port 5300 in the firewall

ufw
sudo ufw deny 5300/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 5300 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 5300 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 5300' -Direction Inbound -Protocol TCP -LocalPort 5300 -Action Block
ufw
sudo ufw deny 5300/udp
iptables
sudo iptables -A INPUT -p udp --dport 5300 -j DROP
nftables
sudo nft add rule inet filter input udp dport 5300 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 5300' -Direction Inbound -Protocol UDP -LocalPort 5300 -Action Block

Related ports

5298presence5299nlg-data5301hacl-gs5302hacl-cfg

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