As a DevOps engineer, it's essential to have a solid understanding of default port numbers used in various technologies. Here are some key ones you should be familiar with: * HTTP: 80 * HTTPS: 443 * SSH: 22 * RDP: 3389 * FTP: 21 * SFTP: 22 * Telnet: 23 * SMTP: 25 * DNS: 53 * NFS: 2048, 2049, 111 For CI/CD tools: * Jenkins: 8080 (default), 8443 (HTTPS) * GitLab CI: 80 (HTTP), 443 (HTTPS) For SonarQube: * 9000 For Artifact Repositories: * Nexus Repository: 8081 (default for HTTP) * JFrog Artifactory: 8081 (for HTTP) and 443 (for HTTPS) For Containerization and Orchestration: * Docker: 2375 (HTTP), 2376 (HTTPS) * Kubernetes: 6443, 10250, 10256 * Etcd: 2379 (client) and 2380 (peer) For Monitoring and Logging: * Prometheus: 9090 * Grafana: 3000 * ELK Stack (Elasticsearch, Logstash, Kibana): Elasticsearch - 9200 (HTTP), 9300 (Transport); Logstash - 5044 (Beats), 5000 (TCP/UDP); Kibana - 5601; Splunk: 8089 * Kiali: Default port 20001 * Jaeger: Jaeger UI - 16686; Jaeger Collector - 14268; Jaeger Agent - 5775 (UDP) Source: https://dev.to/jeyasurya2201/some-key-default-port-numbers-that-a-devops-engineer-should-be-familiar-with-4j5c