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// Network services

Port 3949: Dynamic Routing Information Protocol

Port 3949 is assigned by IANA to drip (Dynamic Routing Information Protocol).

3949

How drip works

Network services
client:3949dripresponse client:3949dripresponse

The client sends a request to port 3949 and the drip 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 3949 dangerous?

We have no specific security note for port 3949. 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 3949

ServicePortTransportDescriptionReferenceUpdated
drip 3949 TCP, UDP Dynamic Routing Information Protocol - 2004-06

// source: IANA service name and port number registry

03 Check it

Which program uses port 3949, and is it reachable?

Linux

sudo ss -ltnup 'sport = :3949'      # process listening on 3949
sudo lsof -nP -i :3949

macOS

sudo lsof -nP -i :3949

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 3949 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 3949
netstat -ano | findstr :3949

From another machine

nmap -p 3949 -sV <host>
sudo nmap -sU -p 3949 <host>
nc -zv <host> 3949

Block it in the firewall

sudo ufw deny 3949/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 3949" -Direction Inbound -LocalPort 3949 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 3949 used for?

Port 3949 is assigned by IANA to drip (Dynamic Routing Information Protocol).

Is port 3949 TCP or UDP?

Port 3949 is registered for TCP and UDP.

Is it safe to open port 3949?

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 3949 is open?

On Linux run "ss -ltnup 'sport = :3949'", on macOS "lsof -nP -i :3949", and on Windows "netstat -ano | findstr :3949" to see the local process. From another machine, "nmap -p 3949 <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

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