National Measurement Laboratory NTP Update: 25 March 2003

The reason for the excess traffic resulting in the need to shut down the 
National Measurement Laboratory's Melbourne, Sydney and Perth NTP servers 
(ntp.nml.csiro.au, ntp.per.nml.csiro.au and ntp.mel.nml.csiro.au) has been 
identified and understood. A certain company has manufactured a piece of network 
hardware with the IP addresses of these NTP servers hard-coded into its 
firmware, and sold many thousands of them. The excess traffic is generated by 
these devices. It is therefore necessary to abandon the previous IP addresses of 
the above three NTP servers. We are still left with the problem of the 
significant bandwidth used by the received traffic, which does not stop (in fact 
it increases significantly) when the servers do not respond.

The Melbourne, Perth and Sydney servers will no longer respond to NTP requests. 
In due course they will operate again under new names and IP addresses. To 
prevent the service (and all its responsible users) being affected by such 
actions in future, future access to the servers will be granted by arrangement 
with us only. We plan to make our service available to systems with fixed IP 
addresses operated by any Australian-based individuals or organisations. We will 
probably be forced to charge a nominal fee for this service.

In the meantime, to ensure continuity of service to responsible users we are 
providing no-charge interim access for Australian users with fixed IP addresses 
to our Stratum 1 servers in Sydney,Brisbane, Adelaide and Perth (the Sydney
and Perth servers have been moved to new addresses). 

If you have a fixed IP address, are Australian based and you require access to 
our NTP servers, please email time@tip.csiro.au with a contact name, address, 
email address and phone number, and the IP addresses of each machine you  want 
to synchronise to our servers. Please try to limit this to two or three systems 
per organisation, and supply time to the rest of your systems from these. We 
will then reply with the names of the servers, and authorise your IP addresses 
for access to these servers. The servers will not respond to unauthorised client 
IPs.

Please note the following:

1) Please remove all references to our previous servers from your existing 
configurations on all systems under your control.
	ntp.nml.csiro.au		130.155.98.1
	ntp.per.nml.csiro.au	130.95.156.206
	ntp.mel.nml.csiro.au	138.194.21.154

The reason we ask you to do this is because although under ordinary 
circumstances your software might poll our servers every few hours, when a 
response is not received many client software packages increase their polling 
rate by a factor of 10 or 100. The traffic generated by this behaviour will be a 
very serious problem if we have to shut down the existing servers, or if there 
is a network outage beyond our control. Consequently, removing your existing 
configuration is very important.

2) Please do not pass on the addresses of the new servers to anyone else, 
firstly because these interim arrangements may change, and secondly because the 
servers will not respond unless we have enabled access for their particular IP 
address. 

3) Please be aware that the final configuration of our servers may be different 
from the interim arrangements. We may need to charge an annual access fee to 
cover operating costs and the substantial administrative overhead associated 
with the "by arrangement only" access policy needed to prevent the excessive use 
that the previous "open slather" access policy encouraged.

I am confident that the CSIRO National Measurement Laboratory's NTP service will 
continue in the long term, in a new form which will not be vulnerable to the 
excessive and uncontrollable useage which the present system has suffered.

Regards,

Peter

---------------------------------------------------------------------------
Dr Peter Fisk
Section Manager: Standards for RF, Microwave, Time and Frequency National 
Measurement Laboratory CSIRO Division of Telecommunications and Industrial 
Physics PO Box 218, Lindfield NSW 2070 Sydney, Australia (street address: 
Bradfield Rd, Lindfield NSW 2070)
Phone: (61 2) 9413 7221
Fax (61 2) 9413 7631
Mobile (61) 0418 693 962
---------------------------------------------------------------------------