From: Mas Kato (tealp729@xxxxxxxx)
Date: Wed May 09 2001 - 06:49:27 GMT-3
How about trying a time-based ACL, something like:
time-range NTP-WINDOW
periodic daily <start_time> to <end_time>
!(multiple periodic entries are allowed)
!
access-list 100 permit udp any any eq ntp time-range NTP-WINDOW
--and then linking it to your 'dialer-list.' I know it's kinda ugly,
but...
For non-DDR interfaces, it's even uglier since the router itself is
sourcing the NTP packets, but maybe a 'local policy route-map' might
work:
time-range NTP-WINDOW
periodic daily <start_time> to <end_time>
!
access-list 100 deny udp any any eq ntp time-range NTP-WINDOW
access-list 100 permit udp any any eq ntp
!
route-map NUKE-NTP permit 10
match ip address 100
set interface null0
!
route-map NUKE-NTP permit 20
!
ip local policy route-map NUKE-NTP
!
Obviously, there's a Catch-22--you'll need to set the proper time up
first...
Regards,
Mas Kato
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Thomas Peroutka
Sent: Tuesday, May 08, 2001 12:36 AM
To: Julie Stewart
Cc: ccielab@groupstudy.com
Subject: Re[2]: ntp poll interval
Hello Julie,
yeah, that4s what it sounds like - but it would be quite a pitty if
you have to poll ntp servers over an ISDN dialup line which would be
almost a leased line then. I wonder why it should not be possible to
change the interval like you can do it in several unix and windows
apps :-(
-- Viele Gr|sse/ Best regards, Thomas mailto:Thomas@Peroutka.deFriday, May 04, 2001, 5:56:05 PM, you wrote:
JS> Thomas,
JS> At http://www.cisco.com/warp/customer/620/ntpassoc.html I found the JS> following:
JS> "The poll field [in the output of 'show ntp associations'] represents the JS> polling interval (in seconds) between NTP poll packets. As the NTP server JS> and client are better synced and there aren't dropped packets, this number JS> increases to a maximum of 1024. The offset field is the calculated offset JS> (in milliseconds) between the client and server time. The client slows down JS> or speeds up its clock to match the server's time value. The offset JS> decreases toward zero over time. It probably will never reach zero since the JS> packet delay between the client and server is never exactly the same, so the JS> client NTP can't ever exactly match its clock with the server's."
JS> That leads me to think that the polling interval and offset are dynamic JS> internals of ntp that change with the state of the connection between the JS> server and client and cannot be changed manually.
JS> Julie
JS> ----- Original Message ----- JS> From: "Thomas Peroutka" <Thomas@Peroutka.de> JS> To: <ccielab@groupstudy.com> JS> Sent: Friday, May 04, 2001 7:31 AM JS> Subject: ntp poll interval
>> Hi there, >> >> does anybody know a possibility to change the ntp polling interval >> (which is 64 s per default and RFC) on a cisco router? >> >> >> -- >> Best regards, >> Thomas mailto:Thomas@Peroutka.de >> **Please read:http://www.groupstudy.com/list/posting.html JS> **Please read:http://www.groupstudy.com/list/posting.html **Please read:http://www.groupstudy.com/list/posting.html **Please read:http://www.groupstudy.com/list/posting.html
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