[dns-operations] Random question about Google resolver behaviour and long-lived TCP sessions

Alexander Dupuy alexdupuy at google.com
Fri Sep 27 16:19:24 UTC 2019


Tony Finch wrote:
>
> So I wonder if Google have implemented EDNS TCP keepalive. If you change
> what BIND calls tcp-advertised-timeout, do Google's TCP connection
> lifetimes change to match?


Google Public DNS has not implemented EDNS TCP keepalive, neither as a
server for its clients, nor in its TCP connections to authoritative
servers. Has BIND added support on its client side, or only as a DNS
server? It seems like Unbound has client and server-side support (
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=231283), and the GetDNS
client code also supports it (https://getdnsapi.net/releases/getdns-0-9-0/)
but those are the only ones I found. I don't see any implementations of RFC
8490 (DNS Stateful Operations).

In any case, as I wrote before, the TCP connections Jake is seeing are not
from Google Public DNS, and quite possibly not even DNS at all (let alone
EDNS).

@alex
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.dns-oarc.net/pipermail/dns-operations/attachments/20190927/5a2bc6da/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 4849 bytes
Desc: S/MIME Cryptographic Signature
URL: <https://lists.dns-oarc.net/pipermail/dns-operations/attachments/20190927/5a2bc6da/attachment.bin>


More information about the dns-operations mailing list