Weird Ping Behavior

rbellamy · Post by **rbellamy** » 19. Jul 2010, 21:48

When I try to ping an address on my corporate network, and I use the DNS name, the replies are erratic (lost packets, when there should be NONE) and have high latency (the reply says ~42ms, but the total time is HUGE).

This is what it looks like when just pinging the IP address - everything looks fine. Note the total time of 12k ms:

Code: Select all

rbellamy@DUMUZID ~> ping 10.69.2.11
PING 10.69.2.11 (10.69.2.11) 56(84) bytes of data.
64 bytes from 10.69.2.11: icmp_seq=1 ttl=62 time=42.2 ms
64 bytes from 10.69.2.11: icmp_seq=2 ttl=62 time=42.9 ms
64 bytes from 10.69.2.11: icmp_seq=3 ttl=62 time=42.0 ms
64 bytes from 10.69.2.11: icmp_seq=4 ttl=62 time=40.9 ms
64 bytes from 10.69.2.11: icmp_seq=5 ttl=62 time=41.7 ms
64 bytes from 10.69.2.11: icmp_seq=6 ttl=62 time=42.9 ms
64 bytes from 10.69.2.11: icmp_seq=7 ttl=62 time=41.3 ms
64 bytes from 10.69.2.11: icmp_seq=8 ttl=62 time=41.5 ms
64 bytes from 10.69.2.11: icmp_seq=9 ttl=62 time=42.1 ms
64 bytes from 10.69.2.11: icmp_seq=10 ttl=62 time=41.9 ms
64 bytes from 10.69.2.11: icmp_seq=11 ttl=62 time=41.2 ms
64 bytes from 10.69.2.11: icmp_seq=12 ttl=62 time=42.1 ms
64 bytes from 10.69.2.11: icmp_seq=13 ttl=62 time=49.8 ms
^C
--- 10.69.2.11 ping statistics ---
13 packets transmitted, 13 received, 0% packet loss, time 12023ms
rtt min/avg/max/mdev = 40.908/42.548/49.813/2.176 ms

And here's what it looks like while pinging via a DNS name. Of particular note is the time of 58k ms, almost 5 TIMES the total time while pinging with just the IP address.

Code: Select all

rbellamy@DUMUZID ~> ping test.local
PING test.local (10.69.2.11) 56(84) bytes of data.
64 bytes from 10.69.2.11: icmp_seq=1 ttl=62 time=40.7 ms
64 bytes from 10.69.2.11: icmp_seq=2 ttl=62 time=43.4 ms
64 bytes from 10.69.2.11: icmp_seq=3 ttl=62 time=41.6 ms
64 bytes from 10.69.2.11: icmp_seq=6 ttl=62 time=43.0 ms
64 bytes from 10.69.2.11: icmp_seq=7 ttl=62 time=42.3 ms
64 bytes from 10.69.2.11: icmp_seq=8 ttl=62 time=41.3 ms
64 bytes from 10.69.2.11: icmp_seq=9 ttl=62 time=42.8 ms
64 bytes from 10.69.2.11: icmp_seq=10 ttl=62 time=43.4 ms
64 bytes from 10.69.2.11: icmp_seq=11 ttl=62 time=43.6 ms
64 bytes from 10.69.2.11: icmp_seq=12 ttl=62 time=42.7 ms
64 bytes from 10.69.2.11: icmp_seq=13 ttl=62 time=42.1 ms
^C64 bytes from 10.69.2.11: icmp_seq=14 ttl=62 time=40.7 ms

--- test.local ping statistics ---
14 packets transmitted, 12 received, 14% packet loss, time 57559ms
rtt min/avg/max/mdev = 40.749/42.345/43.679/1.023 ms

What's up with that? The individual RTT is consistent between the two pings...