www.1und1.de has no NS records.
NS records for this zone are defined at 1und1.de.
NS records for this zone are defined at 1und1.de.
Question and response
Question
dig www.1und1.de. NS
Answer
The response has no answer records.
Authority
1und1.de. 600 SOA ns-1and1.ui-dns.de. dnsadmin.1und1.de. 2013092352 10800 3600 604800 600
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0