spf.penno365.isc.upenn.edu has no NS records.
NS records for this zone are defined at upenn.edu.
NS records for this zone are defined at upenn.edu.
Question and response
Question
dig spf.penno365.isc.upenn.edu. NS
Answer
The response has no answer records.
Authority
upenn.edu. 600 SOA ipam2.nnn.upenn.edu. hostmaster.upenn.edu. 2002406390 10800 3600 604800 600
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0