3 ms·
DNS has always supported TCP. RFC 1034, published in 1987, made it a requirement. DNS uses TCP when replies exceed 512 bytes(barring EDNS0.) DNS also uses TCP f
by bogomipz 4y ago
DNS has always supported TCP. RFC 1034, published in 1987, made it a requirement. DNS uses TCP when replies exceed 512 bytes(barring EDNS0.) DNS also uses TCP for zone transfers. There's even a bit called the TC(truncate) bit which when set in a response informs the client to use TCP.