ns.cust.t4tel.com has no NS records.
NS records for this zone are defined at cust.t4tel.com.
NS records for this zone are defined at cust.t4tel.com.
Question and response
Question
dig ns.cust.t4tel.com. NS
Answer
The response has no answer records.
Authority
cust.t4tel.com. 30 SOA ns.cust.t4tel.com. hostmaster.t4tel.com. 2016062824 3600 600 2600 30
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0