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Network & IT Infrastructure Expert | Mikrotik | VPN | Linux | Cloud With 25 years of experience in IT infrastructure and network engineering, I specialize in designing, securing, and optimizing network systems for businesses of all sizes. Whether you need a reliable VPN solution, a secure network setup, or an optimized server infrastructure, I can help you achieve your goals efficiently. What I Offer: Mikrotik & Network Configuration – Routing, Firewall, VLANs, QoS, Wireless VPN & Secure Networking – WireGuard, OpenVPN, IPsec, GRE tunnels Linux System Administration – Ubuntu, CentOS, Debian, server automation Cloud & Backup Solutions – Veeam, Rsync, ZFS, Proxmox, Disaster Recovery Server & API Hosting – OpenStreetMap servers, self-hosted solutions Troubleshooting & Performance Optimization – Network monitoring, security hardening I have worked with businesses, startups, and enterprise clients to ensure their IT infrastructure is secure, scalable, and high-performing. My approach is straightforward – I analyze, optimize, and deliver solutions that just work. Let’s connect and discuss how I can help with your project!

My name is Djordje(George) Colic. I live in Serbia. I am windows and linux server system administrator. I have MCSA certificate. For 8 years I was working as system administrator for Mcs systems from San Diego and Miami Lakes IT . This is remote job. I heave experience in using ConnectWise and Ninja RMM as remote management tools. I am logging in to remote networks via ConnectWise or VPN- L2TP/IPsec or OpenVPN and then I use RDP to login to server or any workstation. I am giving support to customers via phone, ConnectWise , RDP or TeamViewer. This support includes their servers, workstations, printers , support with their dedicated applications , office 365. I am giving suport to VOIP customers. They have AT&T Synpase or SkyTalk phone system. Synapse Gateways are PSTN 67010 or SIP 67070. Routers: I was working with SonicWall , Peplink , Mikrotik routers . I am in charge for the maintenance of customer’s and office servers and workstations . For automation tasks I am using batch and powershell scripts. Server OS: Windows Server 2016 or 2012. Workstations: windows 10 or 7. Linux server OS: Red Hat . I am logging in to linux servers via SSH to do every day management tasks. Virtualization: VMWare , HyperV. Cloud: I have experience working in AWS . Every network is Domain network with Domain Controller. For file server we are using Synology NAS where important documents are kept on network share. I am also using NAS as VPN server to access remote network. I have knowledge of Java programming and power shell. As DevOPS engineer , I was working for Avi . Our client had Ping Directory , Ping Proxy servers . There were different environments. Server OS: Red Hat Enterprise Linux Server release 7.9 . I was logging into client network via SSH. I have experience in managing linux servers.

I'm network and VOIP engineer with 11 years of experience. Over time I've completed the following certificates: 1. CCNA 2. CCNA security 3. CCNA wireless 4. CCNP - Not certified yet 5. MTCNA 6. MTCRE 7. Linux Essentials 8. LPIC-1 9. Sophos UTM Engineer 10. dCAA 11. 3CX I have experience with the following vendors: Cisco Cisco ACI MikroTIK Sophos UTM Fortinet Checkpoint HP Ubiquiti - Unifi Juniper Alied Telesis PfSense I can help you with: Router configuration WAN Failover VPNs - IPSec, L2TP, OpenVPN etc... Routing - Static, Dynamic including OSPF and BGP MPLS - L3VPN IPSec Firewall - Filter rules, mangle rules etc... FHRP VRF QoS Switch configuration Vlans FHRP Etherchannel Port security Voice Vlan Trunks Troubleshooting Wireless configuration Cisco WLC and LWAPs Ubiquity Unifi - AP, Switch, USG MikroTIK - I have probably configured 500+ MikroTIK devices VOIP 3CX PBX deployment on prem and in cloud Phone management SIP Trunk management DID management IVR Queues Ring Groups etc... Email security Sophos UTM email filter Spam Titan email filter DNS - SPF, DKIM, DMARC Reach out if you find this interesting and we can discuss the details about your project.

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.

👑 Expert Vetted - Top 1% of all Upwork Freelancers - Top Rated Network and Cloud Engineer. - 300+ projects and 7000+ Upwork hours up to date. - 600k+ earned on Upwork. Networking vendors I have worked with: * Cisco, Mikrotik, Fortigate, Ubiquiti, Vyatta, VyOS, pfSense, Sonicwall, Sophos XG, Watchguard, Brocade, Ruckus, HP, Huawei, HPE, Aruba, Arista, etc. Cloud Skills: Terraform (AWS, Azure, GCP) AWS - VPC, EC2, RAM, R53, LB, S3, IAM/SSO, various NGFWs, Terraform. Azure - AD, AADDS, S2S VPNs, VMs, LB, NGFWs, Azure Hub-Spoke, Terraform. GCP - Cloud Compute, Security, NGFWs, Terraform. Digital Ocean Vultr ...

Expert DevOps and Full Stack Engineer with More than 6 years of experience as a Cloud Architect. DevOps expert with a focus on deploying cost effective microservices based solutions in the cloud and local machines ,that can meet the demands of your application while being able to scale. My ability to not only deliver on solutions but also interact like a pro in customer facing situations, makes me an ideal part of any clients team. Whether you need to migrate your workloads to the cloud, optimize your application, well-architect highly-available cloud infrastructure, or automate pipelines and deployments, I have the experience and expertise to help. With most of my projects, I am responsible for everything from ground up. This, of course, includes the development lifecycle, automated release pipelines, automated deployments, version control, and Infrastructure-as-Code. I have vast experience with designing and developing system architectures in Amazon Web Services, Microsoft Azure, and Google Cloud. Have knowledge of technologies which include Docker, Kubernetes, ECS, Azure, Jenkins, Elasticsearch, RDS Aurora, and Terraform, Cloudformation, I am also experienced in Azure devops , Codepipeline, Codebuild, and Ansible.