Help me figure it out: any IP responds to dns queries for me

Question

Domain Name System

Hello everyone,
Here is such a strange thing. I send a dns request to almost any ip on the Internet, and I get a response. Even non-existent addresses and network addresses are answered. What it is? Does the provider have some kind of dns-interceptor? Or maybe it's my adsl router that helps me so much?

$ dig @1.0.0.0 ya.ru

; <<>> DiG 9.9.2-P1 <<>> @1.0.0.0 ya.ru
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 14697
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 8, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;ya.ru.                         IN      A

;; ANSWER SECTION:
ya.ru.                  5032    IN      A       87.250.250.3
ya.ru.                  5032    IN      A       77.88.21.3
ya.ru.                  5032    IN      A       213.180.204.3
ya.ru.                  5032    IN      A       213.180.193.3
ya.ru.                  5032    IN      A       93.158.134.203
ya.ru.                  5032    IN      A       93.158.134.3
ya.ru.                  5032    IN      A       87.250.251.3
ya.ru.                  5032    IN      A       87.250.250.203

;; Query time: 2 msec
;; SERVER: 1.0.0.0#53(1.0.0.0)
;; WHEN: Mon Jun 24 11:20:10 2013
;; MSG SIZE  rcvd: 151

It is noteworthy that requests to the addresses of my local network (for example, “dig @ 10.0.0.10 ya.ru”) do not go through in such a strange way.

Answer 1

Install Wireshark and see who is answering you.

Answer 2

The provider is unlikely to do this. Most likely on your office server/router all dns is wrapped on it. Something like zyxel.ru/kb/1228

Answer 3

Usually adsl-router can do this. He does a redirect to the DNS that he received from the provider.
The +trace option will give additional information:

dig +trace @1.0.0.0 ya.ru

Answer 4

Individual providers redirect DNS to themselves in order to filter individual domains.
Try traceroute -U