Error on ansible -m ping all

gistfile1.txt

[opc@vm04 ansible]$ ansible -m ping all
app02 | UNREACHABLE! => {
    "changed": false,
    "msg": "Failed to connect to the host via ssh: ssh: Could not resolve hostname app02: Name or service not known\r\n",
    "unreachable": true
}
db01 | UNREACHABLE! => {
    "changed": false,
    "msg": "Failed to connect to the host via ssh: ssh: Could not resolve hostname db01: Name or service not known\r\n",
    "unreachable": true
}
app01 | UNREACHABLE! => {
    "changed": false,
    "msg": "Failed to connect to the host via ssh: ssh: Could not resolve hostname app01: Name or service not known\r\n",
    "unreachable": true
}
lb01 | UNREACHABLE! => {
    "changed": false,
    "msg": "Failed to connect to the host via ssh: ssh: Could not resolve hostname lb01: Name or service not known\r\n",
    "unreachable": true
}
control | SUCCESS => {
    "changed": false,
    "ping": "pong"
}