bind 9 can not balance load with mode order cyclic
I configured bind as dns server on centos 8 and create a zone file named test.com.zone,the contents as follow:
$TTL 1D
@ IN SOA test.com. root.test.com. (
2020072603 ; serial
1D ; refresh
1H ; retry
1W ; expire
3H ) ; minimum
@ IN NS master.test.com.
@ IN NS slave.test.com.
slave IN A 100.100.5.21
master IN A 100.100.5.22
www IN A 101.101.5.21
www IN A 101.101.5.22
www IN A 101.101.5.23
www IN A 101.101.5.24
www IN A 101.101.5.25
www IN A 101.101.10.245
www IN A 101.101.10.246
www IN A 101.101.10.247
www IN A 101.101.10.248
www IN A 101.101.10.249
the Subnet Mask of ip in resource records above is all 16 bits,when i ping www.test.com from client for 10 times,the ip it allocates is 101.101.5.21 for 6 times and 101.101.5.22~25,it can not allocate the ip of 101.101.10.x,is it any limit for the ip in resource records? and then I modified the resource records in zone file as follow:
www IN A 101.101.5.21
www IN A 101.101.5.22
www IN A 101.101.5.23
www IN A 101.101.5.24
www IN A 101.101.5.25
www IN A 101.101.5.26
www IN A 101.101.5.27
www IN A 101.101.5.28
www IN A 101.101.5.29
www IN A 101.101.5.30
and I also ping www.test.com from client for 10 times,when the clients' operarte system is centos 8,it can Poll all the ip(101.101.5.2130) correctly,but when the clients' operarte system is centos 7,the ip it allocates is 101.101.5.21 for 5 times and 101.101.5.2226,why does it happen?