ntp configuration

[Jose Salazar]

Hello

I have an internal network with 2 routers and 2 switches 

I want to use one of the routers as ntp master 4

I configured with these commands:

(config)ntp source gigabitEthernet 0/0/0.10

this sub-interface contains the IP 192.168.1.5 which is configured also in the internal ospf to the other router

(config)ntp master 4

(config)ntp server 192.168.1.5

this is in the router1 but when I go to the router 2 I configured

(config)ntp server 192.168.1.5

but the time is not synchronized 

in the router 1 when I run show ntp association I see:

address ref clock st when poll reach delay offset disp
*~127.127.1.1 .LOCL. 3 15 16 177 0.000 0.000 63.693
~192.168.1.5 .INIT. 16 - 1024 0 0.000 0.000 15937.
* sys.peer, # selected, + candidate, - outlyer, x falseticker, ~ configured

What is the IP 127.127.1.1????

what is missing in my conf?

how can delete 127.127.1.1 from the list?

I tried 

(config)no ntp association (doesn't exist)

(config)no ntp source 127.127.1.1 didn't work

(config)no ntp server 127.127.1.1  --invalid address

I will appreciate any help

Thanks

Jose

[Deepak Kumar]

Hi, 

*~127.127.1.1 .LOCL. 3 15 16 177 0.000 0.000 63.693

means this router is NTP master. So it is self NTP server details shown here. 

and can you explain that 

(config)ntp master 4

(config)ntp server 192.168.1.5

: is it router self IP???

Regards,

Deepak Kumar

[Jose Salazar]

Hello

The IP 192.168.1.5 is one IP of the router in the sub interface gi 0/0/0.10

I have two routers

questions:

router1 which shows *~127.127.1.1 .LOCL. 3 15 16 177 0.000 0.000 63.693

and where I configured also the line below which I understand is not necessary, isn't it?

(config)ntp server 192.168.1.5

router 2 where I configure also 

config)ntp server 192.168.1.5 to allow synchronize with router 1. Router 2 is in a differnt network 172.16.x.x 

So, What IP do I have to select from the second router to synchronize whit this master NTP? 

[Deepak Kumar]

Hi,

and where I configured also the line below which I understand is not necessary, isn't it?

(config)ntp server 192.168.1.5

Its not required.

What IP do I have to select from the second router to synchronize whit this master NTP? 

: Configure any IP, if NTP is not disabled on an interface but that IP must be reachable from R2.

Regards,

Deepak kumar

[trfinkenstadt]

Could you do a sh ip route 192.168.1.5 from R2?  Make sure you have a path to it.  Conversely, ensure you have a path from R1 back to whatever you might have set up "ntp source" on r2.

[Richard Burts]

The address 127.127.1.1 is a virtual address similar to a loopback (except it is self generated and not manually configured so it does not show up in show run). 127.127.1.1 is automatically generated when you configure the router as master. You certainly do not need the ntp server 192.168.1.5 in the configuration of router 1. We do not know enough about the relationship between router 1 and router 2 to be able to determine what address router 2 should use. The general answer is that any IP address of router 1 which is reachable from router 2 can be used as the ntp server address for router 2.

HTH

Rick