lan7.att.net.co has no NS records.
NS records for this zone are defined at att.net.co.
NS records for this zone are defined at att.net.co.
Question and response
Question
dig lan7.att.net.co. NS
Answer
The response has no answer records.
Authority
att.net.co. 86400 SOA ns3.telmexla.net.co. internet.telmexla.net.co. 2024040104 1200 7200 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0