well, DNS now supports EDNS, which if specified, allows for packets of up to max UDP packets sizes (though in practice this isn't larger than 4096). The larger

well, DNS now supports EDNS, which if specified, allows for packets of up to max UDP packets sizes (though in practice this isn't larger than 4096). The larger a UDP packet, the more likely there will be fragmentation at each hop, thus increasing the risk of losing the packet in transit. To reduce this, staying under the MTU of the network is desirable, 1400-1500 bytes for most people. Though, b/c of jerks DDOSing systems, and reflection/amplification attacks, some DNS servers are requiring TCP for any packets larger than 512.