2 ms·
Query opcodes 3 and 6 through 15 are unassigned [1]. Middlebox brokenness aside [2], a completely new payload could be placed behind a header 0000 7800 0000
by tonyg 8y ago
Query opcodes 3 and 6 through 15 are unassigned [1]. Middlebox brokenness aside [2], a completely new payload could be placed behind a header
0000 7800 0000 0000 0000 0000
Public DNS installations already have to deal with getting unsolicited random crap, so the risk of fatal confusion is low.
[1] https://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml#dns-parameters-5 https://www.iana.org/assignments/dns-parameters/dns-paramete...
[2] Middlebox brokenness is probably the biggest issue with extending or upgrading DNS, though, I suppose
- peterwwillis 8y agoAnd the middlebox brokenness is due to a lack of versioning. Virtually all middlebox brokenness is a result of a lack of versioning and poor upgrade paths - usually from people demanding backwards compatibility above all else.
- tonyg 8y agoI view it as more of a consequence of "fail closed" thinking than a lack of versioning. As we've seen recently with TLS [1], even protocols with explicit versioning suffer from middlebox brittleness. [1] https://news.ycombinator.com/item?id=17298747 https://news.ycombinator.com/item?id=17298747