Worked on the opensourcerouting/frr repository to enhance OSPF NSSA reliability by implementing Type-7 LSA re-origination when NSSA interfaces become operational or recover from downtime. Addressed a critical routing issue where redistributed routes could be missed if an ASBR redistributed while the interface was down, ensuring LSAs are now correctly re-originated upon interface recovery. Expanded Python-based topotest coverage to validate both static and BGP-learned route redistribution, preventing regressions in NSSA behavior. Utilized C programming and network protocol expertise to deliver robust, test-driven improvements, focusing on reliable external route redistribution and maintaining protocol correctness in complex network scenarios.