Networking interview questions

Validate IPv4 dotted-quad and IPv6 addresses, handling octet ranges, leading zeros, and :: zero-group compression.

Build a long-polling loop that re-issues a held request as each returns, advances a cursor, backs off on error, and stops cleanly.

Queue writes while offline and flush them in FIFO order when the network returns, retrying failures without dropping or reordering.

Wrap a WebSocket so it auto-reconnects with exponential backoff, queues sends while down, and re-emits its events.

Run many logical channels over one WebSocket — route each incoming frame to the right channel and clean up on leave.

Resume a dropped connection without gaps — track sequence numbers, request a replay from the last seen, and de-duplicate redelivered messages.