Port 1556 (veritas-pbx, veritas_pbx)

IANA assigns port 1556 to veritas-pbx, veritas_pbx: VERITAS Private Branch Exchange IANA assigned this well-formed service name as a replacement for "veritas_pbx"..

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference

veritas-pbx TCP VERITAS Private Branch Exchange IANA assigned this well-formed service name as a replacement for "veritas_pbx". Stefan Winkel -

veritas_pbx TCP VERITAS Private Branch Exchange
This entry is an alias to "veritas-pbx". This entry is now historic, not usable for use with many common service discovery mechanisms. Stefan Winkel -

veritas-pbx UDP VERITAS Private Branch Exchange IANA assigned this well-formed service name as a replacement for "veritas_pbx". Stefan Winkel -

veritas_pbx UDP VERITAS Private Branch Exchange
This entry is an alias to "veritas-pbx". This entry is now historic, not usable for use with many common service discovery mechanisms. Stefan Winkel -

Registry dates for this port: registered 2004-04.

Check what is listening on port 1556

Linux: is anything listening on TCP 1556?

sudo ss -tlnp 'sport = :1556'

Linux: UDP 1556

sudo ss -ulnp 'sport = :1556'

Linux / macOS: which process owns the port

sudo lsof -nP -i :1556

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':1556 '

Windows (Command Prompt)

netstat -ano | findstr :1556

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 1556 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine

nc -vz -w 5 HOST 1556

From Windows

Test-NetConnection HOST -Port 1556

UDP probe (no reply does not prove it is closed)

nc -vzu -w 5 HOST 1556

Block port 1556 in the firewall

ufw

sudo ufw deny 1556/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 1556 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 1556 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 1556' -Direction Inbound -Protocol TCP -LocalPort 1556 -Action Block

ufw

sudo ufw deny 1556/udp