Apex domains cannot have CNAME records.
Question and response
Question
dig nss.co.il. NS
Answer
nss.co.il. 5 NS ns3.box.co.il.
nss.co.il. 5 NS ns1.box.co.il.
nss.co.il. 5 NS ns2.box.co.il.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0