NTP confirmation ... petr

http://blog.ine.com/2008/07/28/ntp-access-control/

Dear Petr,
Thanks for good explanation.
I have questions

*R1:*
access-list 1 permit 127.127.7.1
access-list 2 permit 150.1.2.2
ntp master
ntp access-group peer 1
ntp access-group serve-only 2

*R2:*
access-list 1 permit 150.1.1.1
ntp source Loopback0
ntp access-group peer 1
ntp server 150.1.1.1

R1 (master) , R2 (client) :
1. why we have " ntp source Loopback0 " in the client only ?
2. Is the 150.1.2.2 ip address of L0 R2 ? or the other interface as long as
in R2 ?
3. if we have " ntp source lo0 " in a router , and we have configured Lo0 ip
address 1.1.1.1 . The other ntp to peer should point to peer's L0 interface
or we can use any ip address on that box/ntp device. ?

R-peer1#
int l0
ip add 1.1.1.1
int e0
ip add 2.2.2.2
int e1
ip add 200.200.200.200
ntp sou loop0
ntp peer 3.3.3.3 ( can we use this ? , as in R-peer2 we don't use "ntp sou
Lo0" )
ntp peer 2.2.2.3

R-peer2#
int l0
ip add 3.3.3.3
int e0
ip add 2.2.2.3
int e1
100.100.100.100
ntp peer 1.1.1.1
ntp peer 2.2.2.2 ( can we have this instead? ) as long as reachable
ntp peer 200.200.200.200 ( can we use this instead? ) as long as reachable

4. what is the benefit of using " ntp sou " and not using " ntp sou " ....

thanks

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Received on Thu Aug 05 2010 - 09:03:36 ART