ping reverse dns

Slightly unexpected hostname lookup on a CNAME.

maven.op is a CNAME to lulu; the reverse DNS points only to lulu.

Someone has already figured out the lulu hostname by the first line of output because it's shown there. But the ping lines for a few seconds show the name I gave and then turn to the "real" hostname (perhaps when a reverse DNS happens? rather than using the name that we looked up forward-wise to begin with?)

No big deal, but slightly unexpected.

benc@utsire:~$ ping maven.ops.xeus.co.uk
PING lulu.xeus.co.uk (46.4.100.47) 56(84) bytes of data.
64 bytes from maven.ops.xeus.co.uk (46.4.100.47): icmp_req=1 ttl=51 time=466 ms
64 bytes from maven.ops.xeus.co.uk (46.4.100.47): icmp_req=2 ttl=51 time=51.1 ms
64 bytes from maven.ops.xeus.co.uk (46.4.100.47): icmp_req=3 ttl=51 time=51.9 ms
64 bytes from lulu.xeus.co.uk (46.4.100.47): icmp_req=4 ttl=51 time=60.1 ms
64 bytes from lulu.xeus.co.uk (46.4.100.47): icmp_req=5 ttl=51 time=96.5 ms
64 bytes from lulu.xeus.co.uk (46.4.100.47): icmp_req=6 ttl=51 time=50.9 ms
64 bytes from lulu.xeus.co.uk (46.4.100.47): icmp_req=7 ttl=51 time=49.5 ms
64 bytes from lulu.xeus.co.uk (46.4.100.47): icmp_req=8 ttl=51 time=50.6 ms

benc@utsire:~$ ping -V
ping utility, iputils-sss20101006

ping error

Got this while pinging Google DNS from my mifi:

64 bytes from 8.8.8.8: icmp_req=302 ttl=50 time=2095 ms
64 bytes from 8.8.8.8: icmp_req=303 ttl=50 time=2107 ms
wrong data byte #52 should be 0x34 but was 0x45
#8      8 9 a b c d e f 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f 20 21 22 23 24 25 26 27
#40     28 29 2a 2b 2c 2d 2e 2f 30 31 32 33 45 0 0 54
64 bytes from 8.8.8.8: icmp_req=305 ttl=50 time=2127 ms
64 bytes from 8.8.8.8: icmp_req=316 ttl=50 time=11091 ms
64 bytes from 8.8.8.8: icmp_req=317 ttl=50 time=10083 ms

Interesting to me that i) ping is doing more checking than I thought, and ii) there are link layers around that corrupt data (rather than drop packets) in reality not just theory.