nsvel1a.tgt.net.ar has no NS records.
NS records for this zone are defined at tgt.net.ar.
NS records for this zone are defined at tgt.net.ar.
Question and response
Question
dig nsvel1a.tgt.net.ar. NS
Answer
The response has no answer records.
Authority
tgt.net.ar. 900 SOA nsvel1a.tgt.net.ar. ddrc.telefonica.com. 119 10800 3600 2419200 900
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0