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Re: Yahoo DNS broken?

  • From: Michael Sinatra
  • Date: Wed Dec 03 15:50:02 2008
On 12/03/08 12:36, Larry Daberko wrote: 
I am unable to resolve www.yahoo.com.  Tracing DNS back from the root
servers shows that www.yahoo.com is a CNAME to www.wa1.b.yahoo.com and
there are no A records for that hostname.

Anyone have more details or a Yahoo contact?  I'm unable to get to their
webpage as it is :-)

-Larry Daberko
iServe Technologies



$ dig @ns1.yahoo.com www.yahoo.com
; <<>> DiG 9.4.2 <<>> @ns1.yahoo.com www.yahoo.com
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 56431
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2
;; WARNING: recursion requested but not available
;; QUESTION SECTION:
;www.yahoo.com. IN A
;; ANSWER SECTION:
www.yahoo.com. 300 IN CNAME www.wa1.b.yahoo.com.
;; AUTHORITY SECTION:
wa1.b.yahoo.com. 300 IN NS yf1.yahoo.com.
wa1.b.yahoo.com. 300 IN NS yf2.yahoo.com.
;; ADDITIONAL SECTION:
yf1.yahoo.com. 1800 IN A 68.142.254.15
yf2.yahoo.com. 1800 IN A 68.180.130.15
;; Query time: 15 msec
;; SERVER: 68.180.131.16#53(68.180.131.16)
;; WHEN: Wed Dec 3 15:34:09 2008
;; MSG SIZE rcvd: 123

but looking up the host itself gives no answer
$ dig @ns1.yahoo.com www.wa1.b.yahoo.com
; <<>> DiG 9.4.2 <<>> @ns1.yahoo.com www.wa1.b.yahoo.com
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 34875
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 2, ADDITIONAL: 2
;; WARNING: recursion requested but not available
;; QUESTION SECTION:
;www.wa1.b.yahoo.com. IN A
;; AUTHORITY SECTION:
wa1.b.yahoo.com. 300 IN NS yf1.yahoo.com.
wa1.b.yahoo.com. 300 IN NS yf2.yahoo.com.
;; ADDITIONAL SECTION:
yf1.yahoo.com. 1800 IN A 68.142.254.15
yf2.yahoo.com. 1800 IN A 68.180.130.15

Well, since ns1.yahoo.com isn't authoritative for wa1.b.yahoo.com, then I wouldn't expect it to have the answer. Trying yf1.yahoo.com:

> dig www.wa1.b.yahoo.com. @yf1.yahoo.com

; <<>> DiG 9.4.2-P1 <<>> www.wa1.b.yahoo.com. @yf1.yahoo.com
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 31055
;; flags: qr aa rd; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;www.wa1.b.yahoo.com.           IN      A

;; ANSWER SECTION:
www.wa1.b.yahoo.com.    60      IN      CNAME   www-real.wa1.b.yahoo.com.
www-real.wa1.b.yahoo.com. 60    IN      A       209.131.36.158

;; Query time: 3 msec
;; SERVER: 68.142.254.15#53(68.142.254.15)
;; WHEN: Wed Dec  3 12:55:24 2008
;; MSG SIZE  rcvd: 76

It's a chain of CNAME records, which isn't very nice, but isn't technically illegal. In most cases, it's resolvable. Not what I would do for a globally-reachable revenue-generating service, but I am sure they have their reasons.

michael