After configuring IPv6 dataplane interface, firewall never uses IPv4 address when PING is used for hostname resolution on management interface of Firewall.

• Management interface is configured with IPv4 address and one of the dataplane interface has IPv6 address configured.
• When ping is used for hostname resolution it uses IPv6 address eventhough management interface is only configured with IPv4 address.
  

  admin@Lab33-26-PA-5420> ping host google.com
  PING google.com(ra-in-f101.1e100.net (2a00:1450:4025:401::65)) 56 data bytes
  From 2607:f388:0:30c::1 (2607:f388:0:30c::1): icmp_seq=1 Destination unreachable: Address unreachable
  From 2607:f388:0:30c::1 (2607:f388:0:30c::1): icmp_seq=5 Destination unreachable: Address unreachable
  From 2607:f388:0:30c::1 (2607:f388:0:30c::1): icmp_seq=8 Destination unreachable: Address unreachable
  ^C
  --- google.com ping statistics ---
  11 packets transmitted, 0 received, +3 errors, 100% packet loss, time 260ms
  pipe 4

• Even after using management IP as source, Firewall uses IPv6 address and also creates session on IPv6.
  

  admin@Lab33-26-PA-5420> ping source 10.194.33.26 host google.com
  PING google.com(ra-in-f113.1e100.net (2a00:1450:4025:401::71)) from 2607:f388:0:30c::1 : 56 data bytes
  ^C
  --- google.com ping statistics ---
  40 packets transmitted, 0 received, 100% packet loss, time 945ms

• Session created by Firewall:
  

  admin@Lab33-26-PA-5420> show session all 
  
  
  --------------------------------------------------------------------------------
  ID          Application    State   Type Flag  Src[Sport]/Zone/Proto (translated IP[Port])
  Vsys                                          Dst[Dport]/Zone (translated IP[Port])
  --------------------------------------------------------------------------------
  50           ping6          ACTIVE  FLOW       2607:f388:0:30c:0:0:0:1[59335]/L3-Trust/58
  vsys1                                          2a00:1450:4025:401:0:0:0:71[28]/L3-Trust

• All Firewalls
  
  • PAN OS 10.2 and later

• The underlying behavior of PING protocol is independent of PANOS. The PING protocol sending only A(IPv4 DNS record) request in 10.1 vs both AAAA(IPv6 DNS record) + A(IPv4 DNS record) request in 10.2  can be attributed to the version change between both the releases.

Panos 10.1 --->
[root@Lab34-188-PA-3260 ~]#  ping -V
ping utility, iputils-s20121221 <<<<

Panos 10.2 --->
[root@Lab33-26-PA-5420 ~]# ping -V
ping utility, iputils-s20180629 <<<<

• We can enable IPv6 on management interface along with dataplane interface and then ping to any hostname which will use management interface IPv6 for DNS resolution.
  Or 
• We can use a dummy IPv6 address on management interface, where only IPv4 resolution will work.