ld4prd1.mx.csod.com has no NS records.
NS records for this zone are defined at csod.com.
NS records for this zone are defined at csod.com.
Question and response
Question
dig ld4prd1.mx.csod.com. NS
Answer
The response has no answer records.
Authority
csod.com. 300 SOA ns1-ext-prd.csod.com. hostmaster.csod.com. 676175 300 60 1209600 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0