NTP Client and Server - Same router?

[Mokhalil82]

Hi

I am planning to setup NTP with Authentication. A router R1 in the DC will get its time from the ISP, then all devices within the DC will get their time from this router.

So can R1 be configured with the server command and get its time from an ISP router, but also act as a NTP server for other clients. This is with configuring authentication so R1 will need to authenticate with the ISP router but clients will authenticate with R1 to get their time?

[balaji.bandi]

Yes possible, Router get the time source from Internet or ISP and Router also act as a NTP Server for internal device for NTP Sync.

[balaji.bandi]

Yes possible, Router get the time source from Internet or ISP and Router also act as a NTP Server for internal device for NTP Sync.

[paul driver]

Hello

Yes depending on you requirement it usually designed in a hierarchical , that is your designated internal primary server(s) will be ruining as clients with external authoritative time servers.

If you have multiple ntp internal master servers then each these will be ntp peers with each other  but servers lower level internal clients.

Example -
Internal ntp server 1
INS1
ntp server  x.x.x.( external master server 1)

ntp server  x.x.x.( external master server 2)

ntp peer x.x.x.( INS2)

Internal ntp server2

INS2
ntp server  x.x.x.( external master server 1)

ntp server  x.x.x.( external master server 2)

ntp peer x.x.x.( INS1)

Ntp client 1
ntp server ( INS1) prefer
ntp server ( INS2)

Ntp client 2
ntp server ( INS2) prefer
ntp server ( INS1)

[Mokhalil82]

I have put together the following configuration. Is there anything anyone would recommend adding or removing

NTP SERVER 1

ntp server x.x.x.x (Internal DC - No Authentication)
ntp authentication-key 1 md5 xxx
ntp max-associations 100
ntp trusted-key 1
ntp trusted-key 2
ntp peer y.y.y.y

NTP SERVER 2

ntp server y.y.y.y (Internal DC - No Authentication)
ntp authentication-key 2 md5 xxx
ntp max-associations 100
ntp trusted-key 1
ntp trusted-key 2
ntp peer x.x.x.x

CLIENTS

ntp authentication-key 1 md5 xxx
ntp authentication-key 2 md5 xxx
ntp authenticate
ntp server x.x.x.x key 1 prefer
ntp server y.y.y.y key 2
ntp trusted-key 1
ntp trusted-key 2