pop.gmail.com NS records

NS Authoritative DNS server
1m
pop.gmail.com has no NS records.
NS records for this zone are defined at gmail.com.
trace pop.gmail.com NS records for gmail.com

Question and response

Question

dig pop.gmail.com. NS

Answer

The response has no answer records.

Authority

gmail.com. 60 SOA ns1.google.com. dns-admin.google.com. 879012124 900 900 1800 60

Additional

. 0 OPT ; payload 512, xrcode 0, version 0, flags 0