Port 4133 (nuts-bootp, nuts_bootp)

IANA assigns port 4133 to nuts-bootp, nuts_bootp: NUTS Bootp Server IANA assigned this well-formed service name as a replacement for "nuts_bootp"..

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference

nuts-bootp TCP NUTS Bootp Server IANA assigned this well-formed service name as a replacement for "nuts_bootp". Martin Freiss 2 -

nuts_bootp TCP NUTS Bootp Server
This entry is an alias to "nuts-bootp". This entry is now historic, not usable for use with many common service discovery mechanisms. Martin Freiss 2 -

nuts-bootp UDP NUTS Bootp Server IANA assigned this well-formed service name as a replacement for "nuts_bootp". Martin Freiss 2 -

nuts_bootp UDP NUTS Bootp Server
This entry is an alias to "nuts-bootp". This entry is now historic, not usable for use with many common service discovery mechanisms. Martin Freiss 2 -

Check what is listening on port 4133

Linux: is anything listening on TCP 4133?

sudo ss -tlnp 'sport = :4133'

Linux: UDP 4133

sudo ss -ulnp 'sport = :4133'

Linux / macOS: which process owns the port

sudo lsof -nP -i :4133

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':4133 '

Windows (Command Prompt)

netstat -ano | findstr :4133

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 4133 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine

nc -vz -w 5 HOST 4133

From Windows

Test-NetConnection HOST -Port 4133

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

nc -vzu -w 5 HOST 4133

Block port 4133 in the firewall

ufw

sudo ufw deny 4133/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 4133 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 4133 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 4133' -Direction Inbound -Protocol TCP -LocalPort 4133 -Action Block

ufw

sudo ufw deny 4133/udp