[ntp:questions] Max number of lines that ntpdc -c monlist could display

Danny Mayer mayer at ntp.isc.org
Sun May 6 19:41:32 UTC 2007

Martin Burnicki wrote:
> Danny Mayer wrote:
>> Ronan Flood wrote:
>>> mayer at ntp.isc.org (Danny Mayer) wrote:
>>>> Eugen COCA wrote:
>>>>> What is the maximum number of lines that
>>>>> ntpdc -c monlist
>>>>> command could display ?
>>>> #define     MAXMONMEM       600     /* we allocate up to 600 structures */
>>> I have that set to 1920 in ntp-4.2.2, which I calculate is the maximum
>>> number of IPv4 addresses that can be returned to ntpdc without changing
>>> the protocol (max 128 UDP packets).  Note that I need to use an earlier
>>> version of ntpdc, which is not IPv6 aware, to get the full list.  I also
>>> had to increase ntpdc's receive socket buffer size to cope
>>> (rbufsize = INITDATASIZE * 9), but that might be an OS issue.
>> Can you file a bug report on this?
> Shouldn't this be handled with bug #286:
> "ntpdc -nc monlist output failure when amount of clients is over 512"
> https://ntp.isc.org/bugs/show_bug.cgi?id=286
> Martin

Yes, almost identical. So Ronan please add your comments to that bug
report. I think that the biggest problem is timeouts on the client side
probably due to the size of the packet with possible additional
limitations by firewalls not expecting such large packets.


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