[ntp:questions] ***SPAM*** Re: Bad NTP servers jeopardizing the pool.ntp.org initiative

Wolfgang S. Rupprecht wolfgang.rupprecht+gnus200703 at gmail.com
Thu Mar 29 03:35:27 UTC 2007

Jan Ceuleers <janspam.ceuleers at skynet.be> writes:
> The pool is essentially a fancy name server. Pool members could use
> the existing dynamic DNS protocol to register their current IP address
> with the pool. Perhaps in addition to registering with their regular
> dynamic DNS provider, if they provide services other than NTP.

I'd played with ddns when it first came out.  The disagreement I had
with it at the time was the injected entries themselves didn't time
out.  Sure the entries had a TTL, but that was for the lifetime for
the remote DNS client's use.  I see that as a bit of a problem here
too, but not one that couldn't be solved by simply validating the
pools registration zone once in a while and deleting any entries for
machines that are non-responsive.

Of course, folks would need to see a need to support the dynamic

> Disadvantages: I don't know whether dynamic DNS servers are readily
> available to be integrated with the rest of the pool server
> software.

I just set up a simple registration scheme here at the wsrcc.com World
Headquarters (population 2 ;-)).  At least for Linux and BSD machines
it isn't too hard.  The program "nsupdate" can be called from a shell
script that can be run at boot time and/or whenever dhclient gets a
new address assignment.  nsupdate and named can share a per-user
secret that will prevent any riff-raff from vandalizing the
registration zone.

I'll append what the dynamic "mobile.wsrcc.com" zone looks like.  It
should be relatively easy to do something like this for pools with
just a small shell script.

Wolfgang S. Rupprecht                http://www.wsrcc.com/wolfgang/

; <<>> DiG 9.3.4 <<>> mobile.wsrcc.com axfr
;; global options:  printcmd
mobile.wsrcc.com.	300	IN	SOA	ns.wsrcc.com. hostmaster.wsrcc.com. 2007032811 3600 900 2419200 300
mobile.wsrcc.com.	300	IN	NS	ns.wsrcc.com.
mobile.wsrcc.com.	300	IN	NS	mgm.mit.edu.
ancho.mobile.wsrcc.com.	300	IN	A
ancho.mobile.wsrcc.com.	300	IN	HINFO	"x86_64" "Linux"
ancho.mobile.wsrcc.com.	300	IN	TXT	"Boot 2007-03-28 13:59:38 -0700"
ancho.mobile.wsrcc.com.	300	IN	AAAA	2001:5a8:4:7d0:215:6dff:fe10:332c
arbol.mobile.wsrcc.com.	300	IN	A
arbol.mobile.wsrcc.com.	300	IN	A
arbol.mobile.wsrcc.com.	300	IN	HINFO	"x86_64" "Linux"
arbol.mobile.wsrcc.com.	300	IN	TXT	"Boot 2007-03-28 12:39:56 -0700"
arbol.mobile.wsrcc.com.	300	IN	TXT	"Shutdown 2007-03-28 13:39:09 -0700"
arbol.mobile.wsrcc.com.	300	IN	AAAA	2001:5a8:4:7d0::1
capsicum.mobile.wsrcc.com. 300	IN	A
capsicum.mobile.wsrcc.com. 300	IN	HINFO	"athlon" "Linux"
capsicum.mobile.wsrcc.com. 300	IN	TXT	"Boot 2007-03-28 11:57:25 -0700"
capsicum.mobile.wsrcc.com. 300	IN	AAAA	2001:5a8:4:7d0:20c:41ff:feeb:aeb9
scoville.mobile.wsrcc.com. 300	IN	A
scoville.mobile.wsrcc.com. 300	IN	HINFO	"i686" "Linux"
scoville.mobile.wsrcc.com. 300	IN	TXT	"Boot 2007-03-28 13:31:07 -0700"
scoville.mobile.wsrcc.com. 300	IN	AAAA	2001:5a8:4:7d0:20c:41ff:fee2:cd4c
mobile.wsrcc.com.	300	IN	SOA	ns.wsrcc.com. hostmaster.wsrcc.com. 2007032811 3600 900 2419200 300
;; Query time: 2 msec
;; WHEN: Wed Mar 28 20:32:44 2007
;; XFR size: 22 records (messages 1)

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