CyberHunter
LinkedIn profile - Bastien Cordier Email: contact@bastiencordier.pro
// Network services

Port 3819: EPL Sequ Layer Protocol

Port 3819 is assigned by IANA to epl-slp (EPL Sequ Layer Protocol).

3819

How epl-slp works

Network services
client:3819epl-slpresponse client:3819epl-slpresponse

The client sends a request to port 3819 and the epl-slp 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
Registered (1024-49151)
Category
Network services
01 Security

Is port 3819 dangerous?

We have no specific security note for port 3819. 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 3819

ServicePortTransportDescriptionReferenceUpdated
epl-slp 3819 TCP, UDP EPL Sequ Layer Protocol - 2004-10

// source: IANA service name and port number registry

03 Check it

Which program uses port 3819, and is it reachable?

Linux

sudo ss -ltnup 'sport = :3819'      # process listening on 3819
sudo lsof -nP -i :3819

macOS

sudo lsof -nP -i :3819

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 3819 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 3819
netstat -ano | findstr :3819

From another machine

nmap -p 3819 -sV <host>
sudo nmap -sU -p 3819 <host>
nc -zv <host> 3819

Block it in the firewall

sudo ufw deny 3819/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 3819" -Direction Inbound -LocalPort 3819 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 3819 used for?

Port 3819 is assigned by IANA to epl-slp (EPL Sequ Layer Protocol).

Is port 3819 TCP or UDP?

Port 3819 is registered for TCP and UDP.

Is it safe to open port 3819?

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 3819 is open?

On Linux run "ss -ltnup 'sport = :3819'", on macOS "lsof -nP -i :3819", and on Windows "netstat -ano | findstr :3819" to see the local process. From another machine, "nmap -p 3819 <host>" shows whether it is reachable.

05 Related
:53 DNS tcp · udp · moderate risk :135 MS RPC tcp · udp · high risk :123 NTP udp · tcp · moderate risk :67 DHCP server udp · tcp · moderate risk :111 rpcbind tcp · udp · high risk :9100 Raw printing (JetDirect) tcp · udp · high risk :631 IPP / CUPS tcp · udp · high risk :5353 mDNS udp · tcp · moderate risk

Latest vulnerability news

All news