F5 Network Engineer
Core4ce is seeking a Senior Enterprise Network Services Engineer to design, implement, and maintain secure and scalable enterprise network infrastructures. The ideal candidate will have a strong background in network engineering, security, routing, firewall management, load balancing, and automation. This role requires deep knowledge of TCP/IP networking, encryption protocols, traffic analysis, scripting, and cloud networking. Additionally, the candidate will be responsible for planning IT security projects, troubleshooting complex network issues, and ensuring compliance with security policies.
Responsibilities
Design, configure, install, and manage enterprise network infrastructure, including routers, switches, firewalls, and load balancers. Plan and schedule the installation or modification of network hardware and software. Implement and maintain secure network configurations across multi-VRF Cisco routers and enterprise environments. Troubleshoot and analyze TCP/IP network traffic, including TCP 3-way handshake, TCP window scaling, and MSS. Capture and analyze network packets using TCPDump (Linux) and Flow Monitor Capture (Cisco ASR). Implement multi-protocol routing solutions with BGP, OSPF, and VRF-based networks. Use Wireshark, TCPDump, and other diagnostic tools for network performance analysis. Perform TLS/SSL handshake troubleshooting and security configuration. *This position is designed to be flexible, with responsibilities evolving to meet business needs and enable individual growth. Network Security & Compliance Configure and maintain firewalls (Palo Alto, Cisco), including security policies, VPNs, and intrusion prevention systems (IPS). Implement AAA technologies (Cisco ISE, LDAP, OTP) for access management. Ensure certificate management and encryption, including TLS/SSL and OpenSSL operations. Install, configure, and troubleshoot digital certificates on F5 LTM/GTM/APM/ASM appliances. Implement F5 Client Constrained Delegation (C3D) for certificate delegation. Enable certificate-based authentication using Client-SSL profiles and APM policies. Deploy and maintain network monitoring, alerting, and repair systems in production environments. Troubleshoot BGP neighbor configurations, VPNv4 unicast summary, and OSPF network participation. Optimize and troubleshoot load balancing solutions and DNS-based traffic management.
Requirements
Minimum 4 years of hands-on experience as a Network Administrator or Network Security Engineer. Secret clearance w/Tier 5 investigation Strong knowledge of OSI and TCP/IP network models, TCP 3-way handshake, and window scaling. Experience with Palo Alto and Cisco firewalls. Experience with F5 LTM, GTM, APM, ASM for load balancing and security. Cisco Certified Network Professional (CCNP) certification or equivalent experience or willingness to get within 45 days of hire. Preferred Strong troubleshooting skills with routing protocols (BGP, OSPF, VRF, LISP). Familiarity with network packet capture tools (TCPDump, Wireshark). Understanding of essential network services (DNS, SMTP, NTP, IMAP, SNMP). Experience in TLS/SSL security, OpenSSL, and certificate management. Experience working with Unix/Linux-based systems. Experience with network automation (REST APIs, Syslog, XML, SNMP). Experience deploying and troubleshooting load-balanced services and SSL certificate management. Why Work for Us? Core4ce is a team of innovators, self-starters, and critical thinkers—driven by a shared mission to strengthen national security and advance warfighting outcomes. We offer: 401(k) with 100% company match on the first 6% deferred, with immediate vesting Comprehensive medical, dental, and vision coverage—employee portion paid 100% by Core4ce Unlimited access to training and certifications, with no pre-set cap on eligible professional development Tuition assistance for job-related degrees and courses Paid parental leave, PTO that grows with tenure, and generous holiday schedules Got a big idea? At Core4ce, The Forge gives every employee the chance to propose bold innovations and help bring them to life with internal backing. Join us to build a career that matters—supported by a company that invests in you. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex (including pregnancy), national origin, disability, veteran status, age, genetic information, or other legally protected status. Apply To This Job