[Pdns-users] greater number of truncated replies with pdns_recursor?
Michael Loftis
mloftis at wgops.com
Fri Mar 24 20:06:21 UTC 2006
--On March 24, 2006 8:39:26 PM +0100 bert hubert
<bert.hubert at netherlabs.nl> wrote:
> What probably happens is that the verizon servers internally remove all
> additional records that would end up beyond 512 bytes.
>
> In other words, the omit all records that are optional and make their
> answer fit in 512 bytes.
>
> If you show the output of the verizon servers, I can confirm and perhaps
> implement this behaviour in 2.9.21.
>
> Thanks for the report!
Output from BIND 8.3.7, BIND 9.2.1, DJB dnscache 1.05, and PDNS 2.9.19
(need to go to 2.9.20....haven't had time yet!). I don't hav ea 2.9.20
machine around. Obviously the behavior changed 'tween 2.9.19 and 2.9.20
AFAICT. Apologies for the dig versions bein ga bit different but I have to
be in areas that each of these servers (or on the server itself) allows
recursion :) For the BIND servers the ADDITIONAL section, as mentioned, is
round robin...as is the order of teh MX section. DJB does NOT round robin
the MX section. Neither does pdns atleast when using that djb as the
backend recursor....now...I've never been 100% clear, so I setup dnscached
and i have PDNS using that via a recursor= line...my understanding
(incorrect?) from the documentation is that's how the recursor works, with
a backend recursor or query cache of somesort...I'm honestly not 100% clear
on this, I just know that it works, and that djb dnscache seems to handle
most/all of the recursive queries via the pdns frontend after pdns does
packet cache/etc.
BIND 8.3.7
d216-220-25-20:~ mloftis$ dig mx earthlink.net
; <<>> DiG 9.2.2 <<>> mx earthlink.net
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 64075
;; flags: qr rd ra; QUERY: 1, ANSWER: 20, AUTHORITY: 2, ADDITIONAL: 2
;; QUESTION SECTION:
;earthlink.net. IN MX
;; ANSWER SECTION:
earthlink.net. 1154 IN MX 5 mxi.earthlink.net.
earthlink.net. 1154 IN MX 5 mxj.earthlink.net.
earthlink.net. 1154 IN MX 5 mxk.earthlink.net.
earthlink.net. 1154 IN MX 5 mx1.earthlink.net.
earthlink.net. 1154 IN MX 5 mx2.earthlink.net.
earthlink.net. 1154 IN MX 5 mx3.earthlink.net.
earthlink.net. 1154 IN MX 5 mx4.earthlink.net.
earthlink.net. 1154 IN MX 5 mx5.earthlink.net.
earthlink.net. 1154 IN MX 5 mx6.earthlink.net.
earthlink.net. 1154 IN MX 5 mx7.earthlink.net.
earthlink.net. 1154 IN MX 5 mx8.earthlink.net.
earthlink.net. 1154 IN MX 5 mx9.earthlink.net.
earthlink.net. 1154 IN MX 5 mxa.earthlink.net.
earthlink.net. 1154 IN MX 5 mxb.earthlink.net.
earthlink.net. 1154 IN MX 5 mxc.earthlink.net.
earthlink.net. 1154 IN MX 5 mxd.earthlink.net.
earthlink.net. 1154 IN MX 5 mxe.earthlink.net.
earthlink.net. 1154 IN MX 5 mxf.earthlink.net.
earthlink.net. 1154 IN MX 5 mxg.earthlink.net.
earthlink.net. 1154 IN MX 5 mxh.earthlink.net.
;; AUTHORITY SECTION:
earthlink.net. 1151 IN NS itchy.earthlink.net.
earthlink.net. 1151 IN NS scratchy.earthlink.net.
;; ADDITIONAL SECTION:
mxi.earthlink.net. 1154 IN A 209.86.93.155
mxj.earthlink.net. 1154 IN A 209.86.93.156
;; Query time: 19 msec
;; SERVER: 10.1.1.10#53(10.1.1.10)
;; WHEN: Fri Mar 24 12:59:48 2006
;; MSG SIZE rcvd: 506
BIND 9.2.1
root at lb0:~# dig mx earthlink.net @127.0.0.1
; <<>> DiG 9.2.1 <<>> mx earthlink.net @127.0.0.1
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20041
;; flags: qr rd ra; QUERY: 1, ANSWER: 20, AUTHORITY: 2, ADDITIONAL: 2
;; QUESTION SECTION:
;earthlink.net. IN MX
;; ANSWER SECTION:
earthlink.net. 1800 IN MX 5 mxe.earthlink.net.
earthlink.net. 1800 IN MX 5 mxf.earthlink.net.
earthlink.net. 1800 IN MX 5 mxg.earthlink.net.
earthlink.net. 1800 IN MX 5 mxh.earthlink.net.
earthlink.net. 1800 IN MX 5 mxi.earthlink.net.
earthlink.net. 1800 IN MX 5 mxj.earthlink.net.
earthlink.net. 1800 IN MX 5 mxk.earthlink.net.
earthlink.net. 1800 IN MX 5 mx1.earthlink.net.
earthlink.net. 1800 IN MX 5 mx2.earthlink.net.
earthlink.net. 1800 IN MX 5 mx3.earthlink.net.
earthlink.net. 1800 IN MX 5 mx4.earthlink.net.
earthlink.net. 1800 IN MX 5 mx5.earthlink.net.
earthlink.net. 1800 IN MX 5 mx6.earthlink.net.
earthlink.net. 1800 IN MX 5 mx7.earthlink.net.
earthlink.net. 1800 IN MX 5 mx8.earthlink.net.
earthlink.net. 1800 IN MX 5 mx9.earthlink.net.
earthlink.net. 1800 IN MX 5 mxa.earthlink.net.
earthlink.net. 1800 IN MX 5 mxb.earthlink.net.
earthlink.net. 1800 IN MX 5 mxc.earthlink.net.
earthlink.net. 1800 IN MX 5 mxd.earthlink.net.
;; AUTHORITY SECTION:
earthlink.net. 1800 IN NS scratchy.earthlink.net.
earthlink.net. 1800 IN NS itchy.earthlink.net.
;; ADDITIONAL SECTION:
mx1.earthlink.net. 1800 IN A 209.86.93.226
mx2.earthlink.net. 1800 IN A 209.86.93.227
;; Query time: 77 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri Mar 24 13:00:22 2006
;; MSG SIZE rcvd: 506
DJB dnscache 1.05
root at lb1:~# dig mx earthlink.net @127.0.0.1
; <<>> DiG 9.2.1 <<>> mx earthlink.net @127.0.0.1
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 16651
;; flags: qr rd ra; QUERY: 1, ANSWER: 20, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;earthlink.net. IN MX
;; ANSWER SECTION:
earthlink.net. 585 IN MX 5 mxd.earthlink.net.
earthlink.net. 585 IN MX 5 mxe.earthlink.net.
earthlink.net. 585 IN MX 5 mxf.earthlink.net.
earthlink.net. 585 IN MX 5 mxg.earthlink.net.
earthlink.net. 585 IN MX 5 mxh.earthlink.net.
earthlink.net. 585 IN MX 5 mxi.earthlink.net.
earthlink.net. 585 IN MX 5 mxj.earthlink.net.
earthlink.net. 585 IN MX 5 mxk.earthlink.net.
earthlink.net. 585 IN MX 5 mx1.earthlink.net.
earthlink.net. 585 IN MX 5 mx2.earthlink.net.
earthlink.net. 585 IN MX 5 mx3.earthlink.net.
earthlink.net. 585 IN MX 5 mx4.earthlink.net.
earthlink.net. 585 IN MX 5 mx5.earthlink.net.
earthlink.net. 585 IN MX 5 mx6.earthlink.net.
earthlink.net. 585 IN MX 5 mx7.earthlink.net.
earthlink.net. 585 IN MX 5 mx8.earthlink.net.
earthlink.net. 585 IN MX 5 mx9.earthlink.net.
earthlink.net. 585 IN MX 5 mxa.earthlink.net.
earthlink.net. 585 IN MX 5 mxb.earthlink.net.
earthlink.net. 585 IN MX 5 mxc.earthlink.net.
;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri Mar 24 12:58:44 2006
;; MSG SIZE rcvd: 431
And PDNS 2.9.19
root at lb1:~# dig mx earthlink.net
; <<>> DiG 9.2.1 <<>> mx earthlink.net
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 25008
;; flags: qr rd ra; QUERY: 1, ANSWER: 20, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;earthlink.net. IN MX
;; ANSWER SECTION:
earthlink.net. 442 IN MX 5 mxd.earthlink.net.
earthlink.net. 442 IN MX 5 mxe.earthlink.net.
earthlink.net. 442 IN MX 5 mxf.earthlink.net.
earthlink.net. 442 IN MX 5 mxg.earthlink.net.
earthlink.net. 442 IN MX 5 mxh.earthlink.net.
earthlink.net. 442 IN MX 5 mxi.earthlink.net.
earthlink.net. 442 IN MX 5 mxj.earthlink.net.
earthlink.net. 442 IN MX 5 mxk.earthlink.net.
earthlink.net. 442 IN MX 5 mx1.earthlink.net.
earthlink.net. 442 IN MX 5 mx2.earthlink.net.
earthlink.net. 442 IN MX 5 mx3.earthlink.net.
earthlink.net. 442 IN MX 5 mx4.earthlink.net.
earthlink.net. 442 IN MX 5 mx5.earthlink.net.
earthlink.net. 442 IN MX 5 mx6.earthlink.net.
earthlink.net. 442 IN MX 5 mx7.earthlink.net.
earthlink.net. 442 IN MX 5 mx8.earthlink.net.
earthlink.net. 442 IN MX 5 mx9.earthlink.net.
earthlink.net. 442 IN MX 5 mxa.earthlink.net.
earthlink.net. 442 IN MX 5 mxb.earthlink.net.
earthlink.net. 442 IN MX 5 mxc.earthlink.net.
;; Query time: 1 msec
;; SERVER: 216.129.251.13#53(216.129.251.13)
;; WHEN: Fri Mar 24 13:01:07 2006
;; MSG SIZE rcvd: 431
>
> --
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