[dns-operations] Using all the addresses of every name server? (Was: ANY efforts at taking additional responses more compact?

[Fred Morris]

On Monday 12 September 2016 08:36, Paul Vixie wrote:
> > I would not recommend imputing any shared state across multiple
> > addresses associated with a given name.  ...
> 
> that ship has already sailed, so, the expectation must remain reasonable.

I would assume that if shared state is reasonable across multiple addresses, 
then it is reasonable for it to hold for single addresses. However the world 
hasn't fallen over because, for example, 8.8.8.8 doesn't always return 
consistent answers. It might help if you explained exactly what shared state 
concerned you. Obviously TCP isn't assuming shared state: nobody's randomly 
firing packets in a TCP stream at different addresses and expecting them to 
get reassembled correctly. Servers can crash; I haven't see anything in the 
specs about maintaining state across restarts.

--

Fred Morris

--

; <<>> DiG 9.9.4-rpz2.13269.14-P2 <<>> @8.8.8.8 athena.m3047.net
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 49386
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;athena.m3047.net.              IN      A

;; ANSWER SECTION:
athena.m3047.net.       21599   IN      A       209.221.140.128

;; Query time: 3145 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Sep 12 09:58:21 PDT 2016
;; MSG SIZE  rcvd: 61




; <<>> DiG 9.9.4-rpz2.13269.14-P2 <<>> @8.8.8.8 athena.m3047.net
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 15647
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;athena.m3047.net.              IN      A

;; ANSWER SECTION:
athena.m3047.net.       21553   IN      A       209.221.140.128

;; Query time: 42 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Sep 12 09:59:07 PDT 2016
;; MSG SIZE  rcvd: 61




; <<>> DiG 9.9.4-rpz2.13269.14-P2 <<>> @8.8.8.8 athena.m3047.net
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 32343
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;athena.m3047.net.              IN      A

;; ANSWER SECTION:
athena.m3047.net.       21560   IN      A       209.221.140.128

;; Query time: 58 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Sep 12 09:59:08 PDT 2016
;; MSG SIZE  rcvd: 61