vlan100.nw.core-fo.fri2.verisign.com has no NS records.
NS records for this zone are defined at verisign.com.
NS records for this zone are defined at verisign.com.
Question and response
Question
dig vlan100.nw.core-fo.fri2.verisign.com. NS
Answer
The response has no answer records.
Authority
verisign.com. 86400 SOA av1.nstld.com. mdnshelp.verisign.com. 1773447546 300 7200 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0