Unable to ping hostname.local As seen below the given hostname is not pingable presently.  

19:42:43/lib $hostname
mellyrn.local
19:42:55/lib $ping mellyrn.local
ping: cannot resolve mellyrn.local: Unknown host


Note that the internet IS reachable:

19:43:02/lib $ping www.oracle.com
PING e7075.x.akamaiedge.net (23.59.198.140): 56 data bytes
64 bytes from 23.59.198.140: icmp_seq=0 ttl=57 time=5.872 ms
64 bytes from 23.59.198.140: icmp_seq=1 ttl=57 time=5.735 ms
64 bytes from 23.59.198.140: icmp_seq=2 ttl=57 time=5.824 ms
^C
--- e7075.x.akamaiedge.net ping statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 5.735/5.810/5.872/0.057 ms


Let us take a look at the net config:

19:44:54/lib $ifconfig -a
    .. 
en0: flags=8863&lt;UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST&gt; mtu 1500
    ether b8:f6:b1:15:dd:bf
    inet 192.168.255.170 netmask 0xfffffc00 broadcast 192.168.255.255
    media: autoselect
    status: active
I do not have an answer of why this situation occurred.  However,  the problem was corrected by restarting networking:

 $sudo ifconfig en0 down
 $sudo ifconfig en0 up