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System Engineer/ Cisco engineer for 10 years now. Proxmox master proffieciency and deploying Ceph clusters Linux master usage- Ubuntu,Centos,Gentoo Worked on administration of Windows machines from Xp to 10 now. NAS intermediate proficiency(QNAP expert, Synology and FreeNAS/Openmediavault intermediate) Cisco stenghts: Wireless(controller and access points), Voice(Callmanager,CallCenter, H.323 voice gateways), routing and switching(L3VPN,VLANs), security(ASA configuration)

Skilled System Administrator and Network Engineer with over 20 years of hands-on experience, adept at organizing networks for single-office environments or multiple offices connected via VPN. I am highly proficient in Unix system administration (Linux and FreeBSD), covering DNS, DHCP, LAMP/LEMP, FTP, SMTP, SNMP, ACLs, firewalls, and NAT, BGP. My expertise also extends to major cloud platforms (AWS, Vultr, DigitalOcean) and virtualization technologies (vSphere, Hyper-V, Proxmox), as well as monitoring tools (Zabbix) and VoIP/IP telephony systems (Asterisk, FreePBX). Here is what past clients have said about my work: - “Pavel was fantastic! My project hit a snag and I needed an FTP server configured quickly. He jumped in immediately, resolved the issue in no time, and answered all my questions in a friendly manner. This guy is a real problem solver!” - “Very smart when it comes to Linux systems—was able to help with our issue.” - “A very skilled and professional expert who solved all additional and unexpected problems with patience. He overdelivered, and I highly recommend working with him!” - “The problem was solved quickly and efficiently.” - “Pavel did a great job tracing the problem and solving it.” - “Pleasure to work with.” I take pride in my ability to quickly diagnose issues, implement reliable solutions, and consistently exceed client expectations.

More than 20 years of working experience in networking and server administration. Administering and scripting networking applications, database applications, web applications and internet & intranet servers In position of expert engineer for networking infrastructure, IT security expert and senior linux/windows/OSX administrator In charge of designing of LAN/MAN/WAN networking infrastructure, designing and implementation of fiberoptic backbone and copper networking installation. Administration of linux servers and networking devices (switches, routers, firewalls, NAS) am in charge of more than 150 linux servers, both physical and virtual Working with L2/L3 switches, routers, firewalls, NAS devices, switching&routing protocols (RIP, OSPF, SNMP, IGRP/EIGRP, VTP, BGP). Certified Cisco and Mikrotik networking engineer. OS platforms - Red Hat/Centos, Debian/Ubuntu, Gentoo, OpenSolaris, BSD flavors, Windows, OSX Server. Networking equipment - Cisco, HP, Mikrotik, ZTE, Huawei Some of the open-source technologies and daemons I have experience with: - bash, perl and python scripting - apache/nginx web servers (standalone, or in backend mode for tomcat, with one or many virtual hosts) - mysql/postgresql database installation and administration - squid (with or without dansguardian+clamav as content filter/realtime AV) - cloud (openstack, AWS, Azure, gcloud, OVH, rackspace, digital ocean....) - snort (with BASE and Snorby as web GUI) and suricata IDS - iptables (with or without web GUI) - BIND (standalone or master/slave) - postfix (as MTA, combined with alot of different tools such as spamassassin, amavis, clamav, roundcube, postfixadmin, dovecot, cluebringer, mailgraph) - zenoss, zabbix and cacti (with plugins and OUIs) - dovecot (as pop3/imap server of choice, combined with postfix and amavis, clamav, roundcube, postfixadmin, spamassassin) - amavis (with alot of customized settings for things such as double AV scanning, DKIM support, catching of spam headers...) - spamassassin (standard and heuristic bayesian analysis, fine tuning of scoring, OCR integration, SPF integration....) - ClamAV (using both standard and unofficial virus definitions, making of 0-day virus signatures caught in the wild...) - freeradius (with MySQL backend for AAA) - samba (in all possible variatons - standalone simple CIFS sharing, member of windows AD, standalone AD controller, one of the controllers in windows AD) - pureftpd, vsftpd and proftpd (as standalone servers or with virtual users) - xen, vmware, hyperv and kvm virtualization (stock or Xenserver/Proxmox distributions) - asterisk (via Elastix linux distribution) - roundcube as preferred web-mail interface (with alot of customized plugins) - openmediavault/openfiler linux distros for NAS - HA clustering (failover based on DRBD and heartbeat/pacemaker+corosync) - NUT (daemon for UPS monitoring and controlling) - openvpn (with various configurations and backends) - pptp vpns (with various configs and backends) - all kind of linux distributions - RH, CentOS, openSuSe, Debian, Ubuntu, Gentoo, Arch.... - hardening of linux distributions (iptables, fail2bain, allow/deny mechanism, AIDE, SELinux, AppArmour, occasional pen testing) - puppet automation - rancid (centralized backup of config files) - bacula, urbackup and rsync backup

I have 35+ years experience in network projects including design, implementation, system administration and in software development. For the first 5 years of my career I worked on software development: coding and especially testing. For the last 30 years I'm working on implementation and maintenance of University of Nis WAN. Last 26 years I'm deeply involved in AMRES (Academic Network of Serbia) project. Don't fix it if it ain't broken, don't break it if you can't fix it! SKILLS SUMMARY - Any system administration tasks - Operating Systems: any *nix (Linux, FreeBSD, SGI IRIX, SCO, Solaris, OSX), Windows 3.1/9x/Me/XP/Vista/W7/W8/W10/W11, WinServer NT/2K/2003/2008/2012/2016 - LAN & WAN: Ethernet, Fast Ethernet, Gigabit Ethernet, FDDI and Wireless LANs. T1/T3, SDH/SONET, Frame Relay, WDM, ISDN, ADSL, SHDSL, Cable Modems, Cellular, X.25. - Network Protocols: TCP/IP, IPv6, UDP, OSI, CDP, IP Multicast, IPSec, VoIP, Routing, VLANs, Bridging, Trunking, VPN, SNA, DLS - Network Services & servers: SMTP/POP3/IMAP, FTP/SFTP, Telnet/SSH, HTTP/HTTPS, DNS, DHCP, NNTP, NTP, LDAP, SNMP, NETBIOS, Apache, Nginx, MySQL, Plesk, cPanel, Zimbra, VMware, CentOS, Ubuntu, Debian - Network Equipment: various types of modems, firewalls, switches and routers. - Dedicated, VPS and cloud environment servers (Amazon AWS, Google Cloud, MS Azure, Digital Ocean, Linode). - Programming Languages: Unix Shell scripting, BASH, C, Pascal, MS Visual Basic, PHP, HTML, (a bit of Python).

• Expert linux server administrator and DevOps • Apache2 webserver configuration (vhosts, proxy,load balancing) • NGINX webserver configuration from scratch (load balancer, proxy) • Docker containers, debugging, configuring compose files, docker swarm. • Qemu-KVM, Proxmox virtualization, LXC containers. • SFTP configuration for FTP access. • IPtables for blocking traffic in or out. • Issuing and implementation of SSL certificates in Nginx/Apache2. • HTTPS implementation, redirection from Non-SSL to SSL. • Expert skills in configuring/installing Zabbix monitoring. • Installing Zabbix agents, alerting, triggers, log monitoring, graphs. • Implementation of Maxmind GeoIP2 modules Apache/NGINX. • Configuring GeoIP based country blocks, redirections based of client IP's. • Ansible server orchestration. Configuring playbooks. • AWS, Digitalocean, Linode, Azure. • VPN implementation(OpenVPN,wireguard) • Proxy installation/setup • Cloudflare CDN implementation • MySQL, Redis, MongoDB installation/configuration. • Linux server file backups, mysql backups. • Linux shell scripting

Linux System Administrator with B. Com. Sc degree. I've been working on Fiverr (@lukapaunovic) as a freelancer since 2016. I have completed over 3000 orders on this platform and have over 2000 5+ star reviews. Looking forward to bring my expertise to UpWork as well. With over 13 Years of experience, I have worked with more than 5,000 clients in the Web Hosting Industry. I was the owner of two major Web Hosting companies in Serbia with over 1,500 clients each. I am dedicated, passionate and constantly evolving.