abc.			30 IN SOA ac1.nstld.com. info.verisign-grs.com. (
				1714544218 ; serial
				1800       ; refresh (30 minutes)
				900        ; retry (15 minutes)
				604800     ; expire (1 week)
				86400      ; minimum (1 day)
				)

Name servers:
abc.			30 IN NS ac2.nstld.com.
abc.			30 IN NS ac4.nstld.com.
abc.			30 IN NS ac1.nstld.com.
abc.			30 IN NS ac3.nstld.com.