10+ years of experience in linux administration including - Flexible and solid Firewall system by iptables - Samba 4 file serving with multiple domain members - Print Quota system by Papercut - High performance email system supported postfix / qmail and enterprise-grade anti-spam and antivirus email scanning system - Advanced Webmail system by horde 5 - VPN deployment to facilitate secure file access from internet by OpenVPN - Virtualized linux farm deployment by XenServer - Robust realtime backup system by BackupPC / Bareos - Internet fax by Hylafax and avantfax - Wifi authentication by FreeRadius