CloudFlare "Interview Questions"

Marek Majkowski shares a collection of interesting questions about TCP/IP, aiming to encourage readers to review the protocols and spread knowledge about them. The questions cover topics such as lowest TCP port number, URG pointer field usage, RST packet payload, IPv6 flow field usage, IP_FREEBIND socket option, PSH flag functionality, SYN cookies, UDP checksum field, TCP simultaneous open, stupid window syndrome, CWE and ECE flags in TCP header, IP ID field and DF bit, ICMP Path MTU, Linux sysctl settings, incoming TCP connections handling, BGP bogons, MD5 checksums in packets, and differences in checksumming algorithms between IPv4 and IPv6.