fox.r1servers.com has no NS records.
NS records for this zone are defined at r1servers.com.
NS records for this zone are defined at r1servers.com.
Question and response
Question
dig fox.r1servers.com. NS
Answer
The response has no answer records.
Authority
r1servers.com. 360 SOA ns1.fox.r1servers.com. office.hostbulgaria.com. 2026010303 21600 600 1209600 360
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0