2181
Apache ZooKeeper
High RiskTCP — Database
Port Overview
Port Number
2181
Service Name
Apache ZooKeeper
Transport Protocol
TCP
Category
Database
Security Risk
High
Port Range
Registered (1024-49151)
What is Port 2181?
Port 2181 is the default client port for Apache ZooKeeper, a distributed coordination service. Applications like Apache Kafka, Hadoop, and HBase use ZooKeeper for distributed synchronization, configuration management, and leader election. Exposing this port without authentication can allow unauthorized access to distributed system configurations.
TCP
Database
Commonly Used
Security Considerations
Port 2181 (Apache ZooKeeper) is classified as high risk. This port is a common target for automated scanning and brute-force attacks. If you must expose it, restrict access to known IP addresses.
Recommendation: Use firewall rules to whitelist trusted IPs. Enable rate limiting and intrusion detection.