1.2 Transit zone like Trusted Untrusted DMZ

To allow to ping the interface in trust zone:

[edit security zones security-zone trust]
root# show
tcp-rst;
host-inbound-traffic {
system-services {
ping;
}
}
interfaces {
ge-0/0/1.0;
}

or

root# run show configuration security zones security-zone trust | display set
set security zones security-zone trust tcp-rst
set security zones security-zone trust host-inbound-traffic system-services ping
set security zones security-zone trust interfaces ge-0/0/0.0
set security zones security-zone trust interfaces ge-0/0/1.0