There are two issues:
1) in the first command, clockdiff reports a host is down when it isn't (ie
it's pingable) ... should the text say the host is down or just that clock
diff cannot get the time from it... ?
2) the man page refers to the -o2 option, but the executable doesn't have
that option ...
CLOCKDIFF(8) Iputils-ss990107 CLOCKDIFF(8)
clockdiff - Measures clock difference between us and <destination>
with 1msec resolution. Without -o option it uses icmp timestamps, with -o
it uses icmp echo with timestamp IP option.
[root@test95 /root]# clockdiff prep.ai.mit.edu
gnudist.gnu.org is down
[root@test95 /root]# clockdiff -o2 prep.ai.mit.edu
Usage: clockdiff [-o] <host>
[root@test95 /root]# ping prep.ai.mit.edu
PING prep.ai.mit.edu (126.96.36.199) from 188.8.131.52 : 56(84) bytes of
64 bytes from 184.108.40.206: icmp_seq=0 ttl=51 time=117.1 ms
64 bytes from 220.127.116.11: icmp_seq=1 ttl=51 time=190.1 ms
--- prep.ai.mit.edu ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 117.1/153.6/190.1 ms
Fixed in iputils-20000121-1.