Core4ce · 2 weeks ago
F5 Network Engineer
United States
Full-time
Remote
Mid, Senior Level
4+ years expCore4ce 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.
Information Services
No H1B
Security Clearance RequiredU.S. Citizen Only
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
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
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
Qualification
Required
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
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 SaltStack configuration management
Benefits
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
Company
Core4ce
Core4ce is a mission-oriented company that serves as a trusted partner to the national security community.
501-1000 employees
Funding
Current Stage
Late StageLeadership Team
Mike Morehouse
Chief Executive Officer and Managing Partner
Recent News
Business Wire
2025-12-05
Washington Technology
2025-09-27
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