I got a warning on Pingdom called SOA. Can anyone help me with that?

I got these warnings on Pingdom:

Could not find reverse address for 2a00:1450:4010:c08:0:0:0:1b (b.1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.0.c.0.0.1.0.4.0.5.4.1.0.0.a.2.ip6.arpa.).

PTR record(s) for the address could not be found in the .arpa-zone. (ip6.arpa. for IPv6 addresses and in-addr.arpa. for IPv4).

Could not find reverse address for 74.125.203.26 (26.203.125.74.in-addr.arpa.).

PTR record(s) for the address could not be found in the .arpa-zone. (ip6.arpa. for IPv6 addresses and in-addr.arpa. for IPv4).

Could not find reverse address for 2404:6800:4008:c03:0:0:0:1a (a.1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.3.0.c.0.8.0.0.4.0.0.8.6.4.0.4.2.ip6.arpa.).

PTR record(s) for the address could not be found in the .arpa-zone. (ip6.arpa. for IPv6 addresses and in-addr.arpa. for IPv4).

Could not find reverse address for 74.125.203.27 (27.203.125.74.in-addr.arpa.).

PTR record(s) for the address could not be found in the .arpa-zone. (ip6.arpa. for IPv6 addresses and in-addr.arpa. for IPv4).

Could not find reverse address for 2404:6800:4008:c03:0:0:0:1b (b.1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.3.0.c.0.8.0.0.4.0.0.8.6.4.0.4.2.ip6.arpa.).

PTR record(s) for the address could not be found in the .arpa-zone. (ip6.arpa. for IPv6 addresses and in-addr.arpa. for IPv4).

Do anyone know how I could solve them?