ip.pa 站长在吗?有 bug

[1423]

ip.pa.                  21600   IN      NS      ns1.mmrnet.org.
ip.pa.                  21600   IN      NS      ns2.mmrnet.org.

ping -4  ns1.mmrnet.org
PING  (106.54.89.88) 56(84) bytes of data.
64 bytes from 106.54.89.88 (106.54.89.88): icmp_seq=1 ttl=48 time=943 ms
64 bytes from 106.54.89.88 (106.54.89.88): icmp_seq=3 ttl=48 time=943 ms

NS 延迟高丢包多,解析一次要很久

100.189.50.117.in-addr.arpa. 120 IN     PTR     nbghnbk.cn.
100.189.50.117.in-addr.arpa. 120 IN     PTR     cetzcqn.cn.
100.189.50.117.in-addr.arpa. 120 IN     PTR     irhchr.top.

另外这个 PTR 有多个记录,感觉很随意,是不是玩具性质的?