ns2.dominios.uol.com.br has no NS records.
NS records for this zone are defined at dominios.uol.com.br.
NS records for this zone are defined at dominios.uol.com.br.
Question and response
Question
dig ns2.dominios.uol.com.br. NS
Answer
The response has no answer records.
Authority
dominios.uol.com.br. 3600 SOA a10-dns-uolcsfe1.host.intranet. root.uol.com.br. 2015121938 7200 3600 432000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0