[Dnsmasq-discuss] EDNS passthrough

[Philip Rowlands]

Hello,

Not a bug report so much as a query; why does dnsmasq not eagerly attempt to use EDNS when talking to upstream resolvers?

Quoting https://www.mail-archive.com/dnsmasq-discuss@lists.thekelleys.org.uk/msg10449.html :
	EDNS (in this context) is a way for the two ends of a DNS transaction to negotiate the maximum size of reply that can be sent over UDP.

Quoting RFC6891:
   EDNS is a hop-by-hop extension to DNS.  This means the use of EDNS is
   negotiated between each pair of hosts in a DNS resolution process,
   for instance, the stub resolver communicating with the recursive
   resolver or the recursive resolver communicating with an
   authoritative server.

I was mildly surprised to find that dnsmasq will happily "pass through" EDNS, but won't try to use it otherwise if not flagged in the initial query.


Cheers,
Phil