Modules

From SYN to FIN — the complete lifecycle of a TCP connection, traced through the Linux kernel. Learn why packet loss cascades into application latency, why HTTP/2 head-of-line blocking is a TCP problem not an HTTP problem, and how congestion control shapes every connection.

net/ipv4/tcp_input.c

The finite state machine governing every BGP peering session. Understand why 'Active' means the session is failing, how hold timers create silent blackholes, and what happens when a BGP peer goes down.

bgpd/bgp_fsm.c