ping blocks when looking up reverse dns PTR/RR
807559Jun 30 2008 — edited Mar 25 2009Hi!
If someone could shed some light on this behaviour, it would really make my day!
When using ping -s to ping an ip address that doesn't have a PTR RR, ping will timeout until dns timeout.
This would be fine, except that when the replys do show, it's response times are off the roof:
PING 80.79.163.74: 56 data bytes
64 bytes from 80.79.163.74: icmp_seq=0. time=5.65 ms
64 bytes from 80.79.163.74: icmp_seq=1. time=1.38e+05 ms
64 bytes from 80.79.163.74: icmp_seq=2. time=1.37e+05 ms
64 bytes from 80.79.163.74: icmp_seq=3. time=1.36e+05 ms
64 bytes from 80.79.163.74: icmp_seq=4. time=1.35e+05 ms
64 bytes from 80.79.163.74: icmp_seq=5. time=1.34e+05 ms
64 bytes from 80.79.163.74: icmp_seq=6. time=1.33e+05 ms
64 bytes from 80.79.163.74: icmp_seq=7. time=1.32e+05 ms
64 bytes from 80.79.163.74: icmp_seq=8. time=1.31e+05 ms
64 bytes from 80.79.163.74: icmp_seq=9. time=1.30e+05 ms
64 bytes from 80.79.163.74: icmp_seq=10. time=1.29e+05 ms
...
64 bytes from 80.79.163.74: icmp_seq=139. time=236. ms
64 bytes from 80.79.163.74: icmp_seq=140. time=5.92 ms
however, snooping while ping is busy with dns shows that packages do get transmitted and recieved, ping without -s works fine, ping -sn also works fine.
I can reproduce this on 8,9 and 10 of solaris, so I assume this is expected behaviour, although I cannot find any information about this issue, do you know more?
br, Christofer.
Edited by: oholiks on Jun 30, 2008 1:03 AM
added ping example.