On 03/06/2015 17:22, Joe Abley wrote:
> I think there's a baked-in expectation that OPT pseudo-RR is included in > every DNS message, not on every connection (where the transport is > connection-oriented). Joe, Part of the reason this came up is this text in draft-ietf-edns-tcp-keepalive: "DNS clients MAY include the edns-tcp-keepalive option in the first query sent to a server using TCP transport to signal their desire that that specific TCP session be used for multiple DNS transactions." > While the conventional case of resolver-talks-to-authority makes this > seem like a highly pedantic observation, we can never be sure of what is > happening behind the curtain; ALGs that bridge between transports > (providing a UDP interface on one side but managing a TCP connection > pool on the other, for example) exist, for example. Yes, an ALG such as this was the most compelling (albeit hypothetical) reason that I could think of for not making this assumption, but then EDNS is *supposed* to be hop-by-hop. kind regards, Ray _______________________________________________ DNSOP mailing list [email protected] https://www.ietf.org/mailman/listinfo/dnsop
