[ntp:questions] Re: Can you test my server please.

Richard B. Gilbert rgilbert88 at comcast.net
Tue Nov 23 00:42:21 UTC 2004


Simon Lyall wrote:

>I'm looking at a few options to deal with people who abuse time servers 
>(specificly the pool.ntp.org ones). One idea I have is to send the wrong 
>time to abusive clients [1] so that the clients owner actually has an 
>incentive to fix their behavour [2].
>
>I've made a slight modification to MSNTP (sntp server) to always return 
>exactly the same time (In June 1998) to the client. I would appreciate if 
>people could point their clients at it (especially Windows based 
>shareware/freeware programs) and let me know what the result is.
>
>The IP of the server is 202.49.59.7 [3] . I would be interested to know 
>what it does both as the sole server configured or when other servers are 
>configured as well.
>
>
>[1] - Probably after sending them a "kiis of death" packet.
>
>[2] - Many clients ignore kod and some will retry forever when you just 
>block them.
>
>[3] - Actually the servers runs on port 11123 but I've setup iptables 
>rules to redirect requests to 202.49.59.7 on port 123 to to port 11123.
>
>
>  
>
I tried it.  Here's the how and the what happened.  
sunblok_$ ntpdate -d 202.49.59.7
22 Nov 19:37:46 ntpdate[17894]: ntpdate 4.2.0 at 1.1161-r Sat Jan 31 
23:23:54 EST 2004 (9)
Looking for host 202.49.59.7 and service ntp
host found : 202.49.59.7
transmit(202.49.59.7)
transmit(202.49.59.7)
transmit(202.49.59.7)
transmit(202.49.59.7)
transmit(202.49.59.7)
202.49.59.7: Server dropped: no data
server 202.49.59.7, port 123
stratum 0, precision 0, leap 00, trust 000
refid [202.49.59.7], delay 0.00000, dispersion 64.00000
transmitted 4, in filter 4
reference time:    00000000.00000000  Thu, Feb  7 2036  1:28:16.000
originate timestamp: 00000000.00000000  Thu, Feb  7 2036  1:28:16.000
transmit timestamp:  c54d04de.b010a09d  Mon, Nov 22 2004 19:37:50.687
filter delay:  0.00000  0.00000  0.00000  0.00000
         0.00000  0.00000  0.00000  0.00000
filter offset: 0.000000 0.000000 0.000000 0.000000
         0.000000 0.000000 0.000000 0.000000
delay 0.00000, dispersion 64.00000
offset 0.000000

22 Nov 19:37:51 ntpdate[17894]: no server suitable for synchronization found
sunblok_$

I hope this exercise is useful for something.



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