Re: ICMP's & IP src addrs


Karl Kleinpaste (triceratops.cis.ohio-state.edu!karl@tut.cis.ohio-state.edu)
15 Sep 88 17:11:43 GMT


tmallory@park-street.bbn.com writes:
> a `ping {-t,-n,-i,} 129.24.15.255' sometimes yields 129.24.15.255 as
> the src IP address on the packet that is being returned...

   Flame: An ICMP echo to a broadcast address should get no response! What an
   incredibly obnoxious thing to do!

This looked just too tempting, so I headed off to one of our Sun-3/180
servers (SunOS 3.5.1) to see what would happen if I abused its client
subnet (12 Sun3/50 clients) in this way. The result was just mighty
entertaining - the `packet loss' statistic is easily the best part,
followed closely by the claimed IP address...

Script started on Thu Sep 15 12:06:42 1988
[12] [12:06pm] tree:/dino0/karl> ping -s 128.146.28.255
PING 128.146.28.255: 56 data bytes
64 bytes from 128.146.28.255: icmp_seq=0. time=0. ms
64 bytes from 128.146.28.255: icmp_seq=0. time=0. ms
64 bytes from 128.146.28.255: icmp_seq=0. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=0. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=0. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=0. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=0. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=0. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=0. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=0. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=0. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=0. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=1. time=0. ms
64 bytes from 128.146.28.255: icmp_seq=1. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=1. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=1. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=1. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=1. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=1. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=1. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=1. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=1. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=1. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=1. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=2. time=0. ms
64 bytes from 128.146.28.255: icmp_seq=2. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=2. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=2. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=2. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=2. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=2. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=2. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=2. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=2. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=2. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=2. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=3. time=0. ms
64 bytes from 128.146.28.255: icmp_seq=3. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=3. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=3. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=3. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=3. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=3. time=20. ms
64 bytes from 128.146.28.255: icmp_seq=3. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=3. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=3. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=3. time=40. ms
64 bytes from 128.146.28.255: icmp_seq=3. time=40. ms
^C
----128.146.28.255 PING Statistics----
4 packets transmitted, 48 packets received, -1100% packet loss
round-trip (ms) min/avg/max = 0/25/40
[13] [12:06pm] tree:/dino0/karl> exit

script done on Thu Sep 15 12:07:01 1988



This archive was generated by hypermail 2.0b3 on Thu Mar 09 2000 - 14:43:30 GMT