portal.tdncss.net has no NS records.
NS records for this zone are defined at tdncss.net.
NS records for this zone are defined at tdncss.net.
Question and response
Question
dig portal.tdncss.net. NS
Answer
The response has no answer records.
Authority
tdncss.net. 1800 SOA blue.foundationdns.com. dns.cloudflare.com. 2398144056 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0