Senior Network Engineer

Cognizant is seeking a Senior Network Engineer to design, implement, secure, operate, and optimize enterprise datacenter, campus, branch, wireless, and hybrid-cloud networks. This role requires advanced hands-on expertise in F5 BIG-IP, Palo Alto Networks, Cisco ACI, Cisco Nexus, Cisco Meraki, cloud networking, and enterprise DDI platforms. The engineer will serve as an L3 escalation point, lead major-incident troubleshooting, execute migrations and lifecycle upgrades, perform root cause analysis, and collaborate with security, cloud, application, server, and architecture teams.

• Own complex P1/P2 incidents involving routing, switching, wireless, firewalls, load balancing, DNS, DHCP, IPAM, VPN, SD-WAN, and hybrid-cloud connectivity.
• Lead troubleshooting bridges, analyze packet captures and telemetry, restore service, document root cause, and implement permanent corrective actions.
• Prepare and execute implementation, validation, risk, dependency, and rollback plans for production changes and maintenance windows.
• Maintain network diagrams, standards, operating procedures, inventory, capacity plans, lifecycle roadmaps, and disaster-recovery documentation.
• Participate in on-call support, vulnerability remediation, compliance reviews, and vendor escalation activities.

• Configure and troubleshoot F5 BIG-IP LTM, including virtual servers, pools, nodes, monitors, profiles, SNAT, persistence, traffic policies, and SSL offload.
• Manage SSL/TLS certificates, ciphers, health checks, high availability, upgrades, backup, and recovery.
• Develop and troubleshoot iRules; experience with F5 DNS/GTM and Advanced WAF/ASM is preferred.
• Resolve latency, session persistence, SSL handshake, health-monitor, and traffic-distribution issues.

• Administer Palo Alto firewalls and Panorama, including zones, security policies, NAT, objects, App-, User-, URL filtering, threat profiles, and logging.
• Troubleshoot sessions, routing, policy matching, NAT, IPsec VPN, Global Protect, and application connectivity using logs, CLI tools, and packet captures.
• Perform PAN-OS upgrades, rulebase cleanup, recertification, migrations, and security-hardening activities.

• Design and troubleshoot Cisco ACI fabrics using APIC, tenants, VRFs, bridge domains, application profiles, EPGs, contracts, filters, VMM integration, and L3
  
  Out.
• Configure Cisco Nexus 3K/5K/7K/9K platforms using VLANs, trunks, vPC, STP, HSRP, OSPF, BGP, VXLAN, and EVPN.
• Troubleshoot endpoint learning, contracts, routing adjacency, fabric health, interfaces, port channels, and Layer 2/Layer 3 connectivity.
• Support data-center migrations, segmentation, fabric expansion, software upgrades, and hardware refresh programs.

• Design, deploy, and administer Cisco Meraki MX security appliances, MS switches, MR wireless access points, and the Meraki Dashboard.
• Configure Auto VPN, SD-WAN, traffic shaping, content and security policies, VLANs, DHCP, site-to-site VPN, client VPN, and high availability.
• Plan wireless networks using RF fundamentals, channel and power optimization, SSIDs, authentication, guest access, and roaming.
• Monitor organization and network health, analyze event logs and packet captures, manage templates and firmware, and troubleshoot branch, LAN, WAN, and Wi-Fi issues.
• Use Meraki APIs and automation workflows for inventory, configuration validation, monitoring, and large-scale deployment.

• Design and support Microsoft Azure and AWS connectivity across cloud and on-premises data centers.
• Azure: VNets, subnets, NSGs, UDRs, Load Balancer, Application Gateway, Azure Firewall, VPN Gateway, Express Route, Private Link, and DNS.
• AWS: VPCs, subnets, route tables, Security Groups, NACLs, Transit Gateway, Elastic Load Balancing, Direct Connect, Route 53, Private Link, and Site-to-Site VPN.
• Troubleshoot asymmetric routing, overlapping address space, DNS, MTU, VPN, firewall, load-balancing, and cloud-to-data-center connectivity.
• Implement automation and Infrastructure as Code using Python, Ansible, Terraform, REST APIs, JSON, YAML, and Git.

• Administer enterprise DDI platforms, preferably Infoblox Grid, including DNS zones and records, DHCP scopes, reservations, failover, IPAM, and role-based access.
• Troubleshoot recursive and authoritative DNS, forwarding, delegation, DNSSEC, DHCP allocation, lease, and address-management issues.
• Maintain address plans, naming standards, DNS/DHCP…