ns1.topnet.com.mx has no NS records.
NS records for this zone are defined at topnet.com.mx.
NS records for this zone are defined at topnet.com.mx.
Question and response
Question
dig ns1.topnet.com.mx. NS
Answer
The response has no answer records.
Authority
topnet.com.mx. 3600 SOA idcdns2.inext.net.mx. mjmorales.inext.net.mx. 2012030600 10800 3600 604800 3600
Additional
. 0 OPT ; payload 2800, xrcode 0, version 0, flags 0