a death loop with DNS query

[Lyle Giese]

On 7/6/2011 5:52 AM, Feng He wrote:
> When I dig this:
>
> dig s1.mytest.blogchina.org +trace
>
> I got many these info:
>
> mytest.blogchina.org.   600     IN      NS      ns1.dnsv5.com.
> mytest.blogchina.org.   600     IN      NS      ns2.dnsv5.com.
> ;; BAD (HORIZONTAL) REFERRAL
> ;; Received 95 bytes from 183.60.59.217#53(ns1.dnsv5.com) in 6 ms
>
> mytest.blogchina.org.   600     IN      NS      ns1.dnsv5.com.
> mytest.blogchina.org.   600     IN      NS      ns2.dnsv5.com.
> ;; BAD (HORIZONTAL) REFERRAL
> ;; Received 95 bytes from 112.90.143.36#53(ns1.dnsv5.com) in 116 ms
>
> mytest.blogchina.org.   600     IN      NS      ns2.dnsv5.com.
> mytest.blogchina.org.   600     IN      NS      ns1.dnsv5.com.
> ;; BAD (HORIZONTAL) REFERRAL
> ;; Received 95 bytes from 180.153.162.153#53(ns2.dnsv5.com) in 27 ms
>
> mytest.blogchina.org.   600     IN      NS      ns2.dnsv5.com.
> mytest.blogchina.org.   600     IN      NS      ns1.dnsv5.com.
> ;; BAD (HORIZONTAL) REFERRAL
> ;; Received 95 bytes from 221.130.12.61#53(ns2.dnsv5.com) in 165 ms
>
> mytest.blogchina.org.   600     IN      NS      ns2.dnsv5.com.
> mytest.blogchina.org.   600     IN      NS      ns1.dnsv5.com.
> ;; BAD (HORIZONTAL) REFERRAL
> ;; Received 95 bytes from 122.225.217.194#53(ns2.dnsv5.com) in 24 ms
>
> mytest.blogchina.org.   600     IN      NS      ns1.dnsv5.com.
> mytest.blogchina.org.   600     IN      NS      ns2.dnsv5.com.
>
>
>
> What does this death loop mean? How it happened?
>
> Thanks.

That is not a loop at all.  If you do an A record query for 
ns1.dnsv5.com and ns2.dnsv5.com, you get four A records returned each.

However at least from here and it appears from where you are doing the 
querys, these name servers are not responding.  So Dig is just trying 
all A records returned.

Lyle Giese
LCR Computer Services, Inc.