saas.silkroad.com has no NS records.
NS records for this zone are defined at silkroad.com.
NS records for this zone are defined at silkroad.com.
Question and response
Question
dig saas.silkroad.com. NS
Answer
The response has no answer records.
Authority
silkroad.com. 900 SOA ns-872.awsdns-45.net. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0