I can configure & troubleshoot in linux server 1. MAIL server [Postfix, Zimbra] 2. DNS server [Primary & Secondary] 3. Web server [WHM {???????cPanel}???????, Apache2, Httpd] 4. Tacacs+ server 5. Free Raious server 6. DHCP server 7. Ftp server 8. Proxy server 9. NFS server 10. Observium server 11. Nagios server 12. Cacti server 13. Yum server etc. 14. File management 15. User and group management 16. Partition management 17. Scheduling 18. Firewall [Selinux, Iptables]