Count is supported in FreeNAS:
Code:
$ ping -c 3 192.168.1.2
PING 192.168.1.2 (192.168.1.2): 56 data bytes
64 bytes from 192.168.1.2: icmp_seq=0 ttl=64 time=0.618 ms
64 bytes from 192.168.1.2: icmp_seq=1 ttl=64 time=0.315 ms
64 bytes from 192.168.1.2: icmp_seq=2 ttl=64 time=0.299 ms
--- 192.168.1.2 ping statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.299/0.411/0.618/0.147 ms
If you want to cancel a ping in a Linux terminal, use Ctrl + C. No idea how it works in a Windows terminal.