dns3.iplanisp.com.ar has no NS records.
NS records for this zone are defined at iplanisp.com.ar.
NS records for this zone are defined at iplanisp.com.ar.
Question and response
Question
dig dns3.iplanisp.com.ar. NS
Answer
The response has no answer records.
Authority
iplanisp.com.ar. 900 SOA dns1.iplanisp.com.ar. hostmaster.iplan.com.ar. 2018122821 3600 600 1400000 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0