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// Network services

Port 8011: The UDP destination port number for the IP/UDP encapsulated BIER Echo Reply message.

Port 8011 is assigned by IANA to bier-echo (The UDP destination port number for the IP/UDP encapsulated BIER Echo Reply message.).

8011

How bier-echo works

Network services
client:8011bier-echoresponse client:8011bier-echoresponse

The client sends a request to port 8011 and the bier-echo service answers.

Transport
UDP
Exposure risk
not rated depends on the program listening
Encryption
Unknownnot stated by the registry
IANA status
Assigned1 registered service
Range
Registered (1024-49151)
Category
Network services
01 Security

Is port 8011 dangerous?

We have no specific security note for port 8011. Its risk depends on the program actually listening on it. General advice for network services services:

  • Answer only the networks that need the service (no open resolvers, relays or reflectors).
  • UDP services can be abused for DDoS amplification: rate-limit or block them at the edge.
  • Disable legacy test services that have no use in production.
02 Registry

IANA registry entries for port 8011

ServicePortTransportDescriptionReferenceUpdated
bier-echo 8011 UDP The UDP destination port number for the IP/UDP encapsulated BIER Echo Reply message. RFC-ietf-bier-ping-29 2026-10-22
-8011-Reserved--

// source: IANA service name and port number registry

03 Check it

Which program uses port 8011, and is it reachable?

Linux

sudo ss -ltnup 'sport = :8011'      # process listening on 8011
sudo lsof -nP -i :8011

macOS

sudo lsof -nP -i :8011

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 8011 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 8011
netstat -ano | findstr :8011

From another machine

nmap -p 8011 -sV <host>
sudo nmap -sU -p 8011 <host>
nc -zv <host> 8011

Block it in the firewall

sudo ufw deny 8011/udp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 8011" -Direction Inbound -LocalPort 8011 -Protocol UDP -Action Block  # Windows
04 FAQ
What is port 8011 used for?

Port 8011 is assigned by IANA to bier-echo (The UDP destination port number for the IP/UDP encapsulated BIER Echo Reply message.).

Is port 8011 TCP or UDP?

Port 8011 is registered for UDP.

Is it safe to open port 8011?

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. Answer only the networks that need the service (no open resolvers, relays or reflectors).

How do I check if port 8011 is open?

On Linux run "ss -ltnup 'sport = :8011'", on macOS "lsof -nP -i :8011", and on Windows "netstat -ano | findstr :8011" to see the local process. From another machine, "nmap -p 8011 <host>" shows whether it is reachable.

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