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// Other services

Port 68: Bootstrap Protocol Client

Port 68 is assigned by IANA to bootpc (Bootstrap Protocol Client).

68

How bootpc works

Other services
client:68bootpcresponse client:68bootpcresponse

The client sends a request to port 68 and the bootpc service answers.

Transport
TCP · UDP
Exposure risk
not rated depends on the program listening
Encryption
Unknownnot stated by the registry
IANA status
Assigned1 registered service
Range
Well-known (0-1023)
Category
Other services
01 Security

Is port 68 dangerous?

We have no specific security note for port 68. Its risk depends on the program actually listening on it. General advice for other services services:

  • Close the port if nothing on the host needs it.
  • Identify the process that listens on it (commands below) before opening it in a firewall.
  • Expose a service only to the networks that use it.
02 Registry

IANA registry entries for port 68

ServicePortTransportDescriptionReferenceUpdated
bootpc 68 TCP, UDP Bootstrap Protocol Client - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 68, and is it reachable?

Linux

sudo ss -ltnup 'sport = :68'      # process listening on 68
sudo lsof -nP -i :68

macOS

sudo lsof -nP -i :68

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 68 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 68
netstat -ano | findstr :68

From another machine

nmap -p 68 -sV <host>
sudo nmap -sU -p 68 <host>
nc -zv <host> 68

Block it in the firewall

sudo ufw deny 68/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 68" -Direction Inbound -LocalPort 68 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 68 used for?

Port 68 is assigned by IANA to bootpc (Bootstrap Protocol Client).

Is port 68 TCP or UDP?

Port 68 is registered for TCP and UDP.

Is it safe to open port 68?

It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Close the port if nothing on the host needs it.

How do I check if port 68 is open?

On Linux run "ss -ltnup 'sport = :68'", on macOS "lsof -nP -i :68", and on Windows "netstat -ano | findstr :68" to see the local process. From another machine, "nmap -p 68 <host>" shows whether it is reachable.

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