Apex domains cannot have CNAME records.
Question and response
Question
dig iucc.ac.il. NS
Answer
iucc.ac.il. 5 NS sdns.iucc.ac.il.
iucc.ac.il. 5 NS iuccdns.bgu.ac.il.
iucc.ac.il. 5 NS lookup.iucc.ac.il.
iucc.ac.il. 5 NS mdns.iucc.ac.il.
iucc.ac.il. 5 NS med1dns.iucc.ac.il.
Authority
The response has no authority records.
Additional
mdns.iucc.ac.il. 5 A 128.139.197.10
sdns.iucc.ac.il. 5 A 128.139.197.11
lookup.iucc.ac.il. 5 A 128.139.34.240
lookup.iucc.ac.il. 5 AAAA 2001:bf8:900:6:0:0:808b:22f0
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0