spf.alumni.cuhk.net has no NS records.
NS records for this zone are defined at alumni.cuhk.net.
NS records for this zone are defined at alumni.cuhk.net.
Question and response
Question
dig spf.alumni.cuhk.net. NS
Answer
The response has no answer records.
Authority
alumni.cuhk.net. 600 SOA ddi-gm1.itsc.cuhk.edu.hk. hostmaster.cuhk.edu.hk. 201701285 1800 900 1209600 600
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0