What is "o-o---preferred---yh---www.google.com"?

Solution 1:

It's a google infrastructure domain. It can be verified using a dig (or dig command in Linux). Read the comments above. :)

You are not supposed to see this domain, because it's usually hidden, but sometimes there might be a glitch in network routing or a server problem of some sort that causes it to be seen.

It looks like you're seeing some infrastructure that's supposed to be under the covers but has escaped. Do happen to have a yahoo-branded connection (ISP)? I ask because of this question: prevent requests to o-o---preferred---bellcanada-yul2---v21---cache.c.pack.google.com – mgkrebbs

From the WHOIS and DNS records, It looks like it has something to do with the domain name:1E100.NET See the explanation here http://support.google.com/answer/174717?hl=en "1e100.net is a Google-owned domain name used to identify the servers in our network" – suit

$ dig o-o---preferred---yh---www.google.com

; <<>> DiG 9.9.2-P1 <<>> o-o---preferred---yh---www.google.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8411
;; flags: qr rd ra; QUERY: 1, ANSWER: 7, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;o-o---preferred---yh---www.google.com. IN A

;; ANSWER SECTION:
o-o---preferred---yh---www.google.com. 300 IN CNAME o-o.preferred.yh.www.google.com.
o-o.preferred.yh.www.google.com. 300 IN A   74.125.139.105
o-o.preferred.yh.www.google.com. 300 IN A   74.125.139.104
o-o.preferred.yh.www.google.com. 300 IN A   74.125.139.147
o-o.preferred.yh.www.google.com. 300 IN A   74.125.139.99
o-o.preferred.yh.www.google.com. 300 IN A   74.125.139.103
o-o.preferred.yh.www.google.com. 300 IN A   74.125.139.106

;; Query time: 33 msec
;; SERVER: 127.0.1.1#53(127.0.1.1)
;; WHEN: Fri Oct 18 09:42:53 2013
;; MSG SIZE  rcvd: 197

Using the whois tool (or whois command) we can verify the IP:

$ whois 74.125.139.105

[...]
NetRange:       74.125.0.0 - 74.125.255.255
CIDR:           74.125.0.0/16
OriginAS:       
NetName:        GOOGLE
NetHandle:      NET-74-125-0-0-1
Parent:         NET-74-0-0-0-0
NetType:        Direct Allocation
RegDate:        2007-03-13
Updated:        2012-02-24
Ref:            http://whois.arin.net/rest/net/NET-74-125-0-0-1


OrgName:        Google Inc.
OrgId:          GOGL
Address:        1600 Amphitheatre Parkway
City:           Mountain View
StateProv:      CA
PostalCode:     94043
Country:        US
RegDate:        2000-03-30
Updated:        2013-08-07
Ref:            http://whois.arin.net/rest/org/GOGL

[...]