Sagar Bairagi
Summary
Network architect with 15+ years designing, building and running global data center, hybrid cloud and enterprise WAN networks. Architects scalable, secure and highly available networks on Cisco ACI, VMware NSX-T, Nexus, AWS, Azure and GCP; turns designs into code with Ansible, Terraform and Python; and leads incident response and change for business-critical services. Cisco CCIE Enterprise Infrastructure #57252 (earned as Routing & Switching); CCNP Data Center; CCIE Data Center written.
Experience
Senior Specialist Cloud Network Engineer
- Design and run the hybrid network between AWS and on-premises data centers built on Cisco ACI.
- Build hybrid connectivity (Site-to-Site VPN and Direct Connect) between AWS and ACI with consistent routing and segmentation policy.
- Deliver applications through AWS Application and Network Load Balancers (ALB/NLB) – secure, scalable and fast.
- Provision VPCs, subnets, route tables, security groups and load balancers with Terraform (infrastructure as code) for repeatable deployments.
- Operate the ACI fabric, Nexus switching and firewall integrations; work with DevOps, Cloud and Security teams on CI/CD for network changes.
Senior Network Manager – Data Center
- Ran four enterprise-scale Vodafone data centers: Cisco ACI Multi-Pod, Nexus 9K/7K, VMware NSX-T, Fortinet and Juniper firewalls, F5 load balancers.
- Automated ACI fabric and tenant builds with Ansible – YAML/JSON templates for VRFs, bridge domains, EPGs, contracts and L3Outs – run through Jenkins and Git with pre-checks and post-checks.
- Integrated NSX-T and HPE networking with the ACI fabrics for consistent policy and secure workload segmentation.
- On-call for P1/P2 incidents across switching, routing and security; root-cause analysis and recovery.
- Wrote Python and Bash tooling for health checks, configuration backups and port monitoring.
Data Center Manager
- Led design, deployment and operation of Cisco ACI fabrics for four large Vodafone core data centers in the UK and Europe.
- Architected a hybrid network joining ACI with VMware NSX-T and AWS, Azure and GCP for application mobility and micro-segmentation.
- Designed tenant-based segmentation separating production, DMZ and user zones.
- Aligned the network architecture with the enterprise cloud strategy and cyber-security compliance alongside global cloud, virtualization and security teams.
Deputy Manager – Network
- Rolled out Cisco DNA Center with SD-Access, integrated with Cisco ISE and wireless controllers for identity-based access, device profiling and secure mobility.
- Implemented VRF-based segmentation and MP-BGP multicast routing for partner and internal networks.
- Designed enterprise-wide IPv4 and IPv6 addressing across data centers and cloud regions.
- Wrote low-level designs, method-of-procedure documents and rollback plans for every build; trained junior engineers.
Network Engineer – L3
- Led Juniper SRX firewall and EX switch deployments across Bangalore, Delhi, Pune, Chennai and Hyderabad.
- Built site-to-site IPsec and SSL VPNs, NAT and URL filtering on Juniper SRX and Sophos; OSPF designs with failover between branches and HQ.
- Ran the corporate network, data centers and multiple AWS VPCs; led L3 escalations and an IPv6 proof of concept.
Server & Network Engineer – L2
- Migrated a global client network from Cisco to Juniper across the UAE, Singapore, the UK, Sweden and the US.
- Designed MPLS VPNv4 (MP-BGP) with custom RD/RT and VRF segmentation; built IPsec site-to-site and remote-access VPNs.
- Took part in disaster-recovery drills; worked with Cisco and carrier partners on critical issues.
Network Team Lead
- Kept the LAN/WAN for 12 branch offices and 5,000+ users at 99.9% uptime.
- VLANs, trunking, port-channels, inter-VLAN routing and ACLs on Cisco Catalyst switching; coordinated ISPs and hardware vendors.
Junior IT Administrator
- L1/L2 network and systems support; switch and router configuration (VLANs, STP/RSTP); monitoring with Nagios, SolarWinds and PRTG.
Network Engineer – L1 Support
- First-level support for Cisco routers and switches: VLANs, IOS upgrades, backups, monitoring and incident escalation.
Certifications
- Cisco CCIE Enterprise Infrastructure #57252 – Cisco Certified Internetwork Expert, earned as CCIE Routing & Switching (lab). Also passed the CCIE Data Center written exam.
- Cisco CCNP Data Center – Cisco Certified Network Professional – Data Center.
- Cisco Certified Specialist – Data Center – Data Center Design, Core and Operations.
- Cisco Certified Specialist – Enterprise Core – Enterprise network core technologies.
- Cisco SVPN – Implementing Secure Solutions with Virtual Private Networks.
- Microsoft Azure AZ-700 – Designing and Implementing Azure Networking Solutions. Plus AZ-900 Fundamentals.
- VMware VCP-NV 2022 – VMware Certified Professional – Network Virtualization (NSX-T).
- Juniper JNCIA-Junos – Juniper Networks Certified Associate – Junos.
- Cisco CCNA – Cisco Certified Network Associate.
Skills
- Routing & switching: BGP, MP-BGP, OSPF, EIGRP, MPLS L3VPN, VRF, EVPN, DMVPN, HSRP / VRRP / GLBP, Multicast
- Data center: Cisco ACI (Multi-Pod), Nexus 9K/7K/5K/2K, VXLAN, vPC, VMware NSX-T, HPE & Arista integration
- Cloud networking: AWS VPC & Transit Gateway, AWS Direct Connect, Site-to-Site VPN, AWS ALB / NLB, Azure networking, GCP, OCI
- Security: Fortinet FortiGate, Cisco ASA & Firepower, Juniper SRX, Check Point, Cisco ISE, IKEv2 / IPsec, SSL VPN
- Load balancing: F5 LTM / GTM, Citrix NetScaler, VMware Avi, AWS ALB / NLB
- Automation & IaC: Ansible, Terraform, Python, Bash, YAML / JSON templates, Git, Jenkins CI/CD
- Campus & SD-WAN: Cisco DNA Center, SD-Access, Wireless LAN controllers, Silver Peak, Cisco vManage
- Monitoring: Cisco ThousandEyes, SolarWinds, PRTG, Stealthwatch, Cacti, Prime Infrastructure
- Process & leadership: ITIL change & incident, ServiceNow / Remedy, MOPs & rollback plans, Design reviews, Mentoring engineers
Education
Bachelor of Engineering, Computer Engineering – Saraswati College of Engineering, Navi Mumbai (University of Mumbai), 2011.
A detailed CV and references are available on request – send me a message.