Crazy Ping Results

["Pete Peterson" <petersonp genrad com>]

I have a very strange problem with "ping" in the 7.2 machine that I just
loaded from scratch.  If I ping by IP, things look normal; if I ping
by name, the name is resolved OK, but I get crazy ping results with
times growing by 4 seconds.  Here is an example pinging a machine on
our local network (one of our name servers).


[root torvalds rc3.d]# host ns1.genrad.com.
ns1.genrad.com. has address 132.223.4.1


[root torvalds rc3.d]# ping 132.223.4.1
PING 132.223.4.1 (132.223.4.1) from 132.223.32.43 : 56(84) bytes of data.
Warning: time of day goes back, taking countermeasures.
64 bytes from 132.223.4.1: icmp_seq=0 ttl=254 time=1.328 msec
64 bytes from 132.223.4.1: icmp_seq=1 ttl=254 time=669 usec
64 bytes from 132.223.4.1: icmp_seq=2 ttl=254 time=738 usec
64 bytes from 132.223.4.1: icmp_seq=3 ttl=254 time=713 usec
64 bytes from 132.223.4.1: icmp_seq=4 ttl=254 time=682 usec

--- 132.223.4.1 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max/mdev = 0.669/0.826/1.328/0.252 ms

**** OK -- that looks normal enough -- now we ping by name ****

[root torvalds rc3.d]# ping ns1.genrad.com
PING ns1.genrad.com (132.223.4.1) from 132.223.32.43 : 56(84) bytes of data.
Warning: time of day goes back, taking countermeasures.
64 bytes from ns1.genrad.com (132.223.4.1): icmp_seq=0 ttl=254 time=708 usec
64 bytes from ns1.genrad.com (132.223.4.1): icmp_seq=1 ttl=254 time=4.023 sec
64 bytes from ns1.genrad.com (132.223.4.1): icmp_seq=2 ttl=254 time=8.043 sec
64 bytes from ns1.genrad.com (132.223.4.1): icmp_seq=3 ttl=254 time=12.062 sec
64 bytes from ns1.genrad.com (132.223.4.1): icmp_seq=4 ttl=254 time=16.083 sec
64 bytes from ns1.genrad.com (132.223.4.1): icmp_seq=5 ttl=254 time=20.102 sec

--- ns1.genrad.com ping statistics ---
31 packets transmitted, 7 packets received, 77% packet loss
round-trip min/avg/max/mdev = 0.708/12062.683/24122.945/8040.418 ms


**** Note that it pinged (pang?) the same address -- the ping shows 6 packets
with adjacent seq numbers, but there are 31 lost packets (why aren't
there seq number gaps?).

Another 7.2 machine on our local net gives normal results, either pinging
by name or by IP.

Does this make any sense to anyone?  Once it's resolved the address, why
should ping care whether you specified a name or an IP?


       pete

--
        pete peterson
        Teradyne, Inc.
        7 Technology Park Drive
        Westford, MA 01886-0033

        pete peterson teradyne com or petersonp genrad com
        +1-978-589-7478 (Teradyne); +1-978-589-2088 (Closest FAX);
        +1-978-589-7007 (Main Teradyne Westford FAX)