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.

• 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.

• 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.
• Performance Monitoring & Troubleshooting
• Deploy and maintain network monitoring, alerting, and repair systems in production environments.
• Troubleshoot BGP neighbor configurations, VPNv4 unicast summary, and OSPF network participation.
• Analyze DUP ACK packets, out-of-order segments, and retransmission issues.
• Optimize and troubleshoot load balancing solutions and DNS-based traffic management.

• Manage and support cloud-based network services across Azure, AWS, and Oracle Cloud.
• Configure and maintain virtualized network appliances in VMware environments.

• Utilize Python and BASH scripting for network automation and troubleshooting.
• Develop scripts using REST APIs, Syslog, XML, and SNMP for automation.
• Use regular expressions (e.g., "*.", "^", "$") for scripting and log parsing.

* This position is designed to be flexible, with responsibilities evolving to meet business needs and enable individual growth.

• 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 scalingli>
• 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

• 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.
• Proficiency in scripting languages (Python, BASH) and automation tools.
• 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.
• Familiarity with multi-cloud networking (Azure, AWS, Oracle Cloud).
• Experience working with Puppet Labs or Salt Stack configuration management

Core4ce is a team of innovators,…