HTTPfy

Port 2564 (hp-3000-telnet)

IANA assigns port 2564 to hp-3000-telnet: HP 3000 NS/VT block mode telnet.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
hp-3000-telnet TCP HP 3000 NS/VT block mode telnet - -
hp-3000-telnet UDP HP 3000 NS/VT block mode telnet - -

Check what is listening on port 2564

Linux: is anything listening on TCP 2564?
sudo ss -tlnp 'sport = :2564'
Linux: UDP 2564
sudo ss -ulnp 'sport = :2564'
Linux / macOS: which process owns the port
sudo lsof -nP -i :2564
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':2564 '
Windows (Command Prompt)
netstat -ano | findstr :2564
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 2564 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 2564
From Windows
Test-NetConnection HOST -Port 2564
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 2564

Block port 2564 in the firewall

ufw
sudo ufw deny 2564/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 2564 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 2564 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 2564' -Direction Inbound -Protocol TCP -LocalPort 2564 -Action Block
ufw
sudo ufw deny 2564/udp
iptables
sudo iptables -A INPUT -p udp --dport 2564 -j DROP
nftables
sudo nft add rule inet filter input udp dport 2564 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 2564' -Direction Inbound -Protocol UDP -LocalPort 2564 -Action Block

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