spf2.barracuda.com has no NS records.
NS records for this zone are defined at barracuda.com.
NS records for this zone are defined at barracuda.com.
Question and response
Question
dig spf2.barracuda.com. NS
Answer
The response has no answer records.
Authority
barracuda.com. 3600 SOA ns1-07.azure-dns.com. root.barracuda.com.barracuda.com. 2041020597 7200 3600 86400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0