spf-mailrouting.isc.upenn.edu. TXT RRSIG NSEC
Question and response
Question
dig spf-listserv.isc.upenn.edu. NSEC
Answer
spf-listserv.isc.upenn.edu. 600 NSEC spf-mailrouting.isc.upenn.edu. TXT RRSIG NSEC
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0