Sr. IPv6 Network Engineer (Fairfax)

US Citizenship required to obtain government clearance.

Position Overview

We are seeking a highly skilled Senior Network Engineer with deep expertise in IPv6 technologies to join our team. This role is critical to driving our projects IPv6 Assessment, Design, and Testing initiatives across the network. The ideal candidate will bring hands-on experience with dual-stack environments, multicast routing, and Cisco platforms, ensuring a seamless and secure transition to next-generation IP networking.

Key Responsibilities

IPv6 Network Assessment

• Conduct comprehensive assessments of the existing network infrastructure to evaluate IPv6 readiness across routers, switches, firewalls, and end-host systems.
• Identify gaps in current IPv4 configurations and develop a prioritized roadmap for IPv6 integration.
• Perform audits of hardware and software compatibility for IPv6 support, including IOS/IOS-XE feature validation.
• Document current-state network topology and provide detailed findings and recommendations to stakeholders.

Network Design

• Architect IPv4/IPv6 dual-stack solutions that ensure backward compatibility while enabling full IPv6 functionality.
• Design scalable IPv6 addressing plans
• Develop multicast routing designs for IPv6 environments.
• Create high-level and low-level design documents (HLD/LLD), including topology diagrams, IP allocation schemes, and routing policy specifications.
• Collaborate with security, systems, and application teams to ensure end-to-end IPv6 compatibility.

Testing & Implementation

• Develop and execute comprehensive test plans for IPv6 deployment scenarios, including dual-stack, tunneling (6in4, GRE, ISATAP), and translation (NAT64/DNS64) mechanisms.
• Perform lab-based proof-of-concept (PoC) testing prior to production deployment.
• Validate multicast functionality, routing protocol behavior and QoS policies in an IPv6 context.
• Troubleshoot complex network issues across dual-stack environments and provide root-cause analysis.
• Develop production migration procedures, including change management documentation and rollback procedures.

General Duties

• Serve as a subject matter expert (SME) for IPv6 and multicast technologies within the project.
• Mentor junior engineers and provide knowledge transfer on IPv6 best practices.
• Participate in change advisory board (CAB) reviews and provide technical input on network changes.

Experience

7+ years of progressive network engineering experience in enterprise or service provider environments

IPv6

Demonstrated hands-on experience with IPv6 addressing, routing, and migration strategies

Dual Stack

Proven experience designing and operating IPv4/IPv6 dual-stack networks

Multicast

Strong knowledge of multicast routing protocols (PIM-SM, IGMP, MLD) in both IPv4 and IPv6

Certification

Cisco CCNP (Enterprise or Service Provider) and/or equivalent industry experience

Routing Protocols

Proficiency with OSPFv2/v3, BGP (including IPv6 address families)

Platforms

Hands-on experience with Cisco routing and switching platforms

Documentation

Ability to produce clear, professional network design documents, test plans, and assessment reports

Preferred Qualifications

• Cisco CCIE (Enterprise Infrastructure or Service Provider) certification
• Experience with network automation tools (Python or Ansible) for IPv6 deployment at scale
• Familiarity with SNMP, NetFlow, and monitoring tools in IPv6 environments
• Experience with security policies in dual-stack networks (ACLs)
• Prior experience leading or participating in large-scale IPv6 migration projects
• Understanding of federal or regulatory compliance frameworks related to IPv6 mandates (e.g., OMB M-21-07)

Education

Bachelor's degree in Computer Science, Information Technology, Network Engineering, or a related field — or equivalent combination of education and experience.

Work Environment

Due to the sensitivity of the work, on-site attendance is mandatory five days a week.