Solved: NTP question

Brent Rockburn · ‎04-08-2010

I would like for my 4507 to be the ntp server for my LAN. It looks like I have to configure the NTP broadcast on a specific interface. So how does that work for the rest of the network or do I have to configure it on every single one of my interfaces?

Jon Marshall · ‎04-08-2010

b.rockburn wrote:

I just want our servers domain controllers and the like to use the core as the ntp server. So configuring the core as an ntp master is the key?

Brent

Yes, but there can be compatability issues between Windows and Cisco, you may need to just test and see what happens. At my last place we had a dedicated time server that we peered a Cisco router to and then peered all our Cisco devices to that router and the Windows guys peered directly with the dedicated time server.

Also are you intending to sync the master 4500 with an internet time server or are you more concerned with just syncing devices to the same time with your LAN ?

Jon

View solution in original post

Jon Marshall · ‎04-08-2010

b.rockburn wrote:

My 4507 is already synched with external ntp sources.

Brent

Great, then you should be all set.

Jon

View solution in original post

Jon Marshall · ‎04-08-2010

b.rockburn wrote:

I would like for my 4507 to be the ntp server for my LAN. It looks like I have to configure the NTP broadcast on a specific interface. So how does that work for the rest of the network or do I have to configure it on every single one of my interfaces?

Brent

You don't need to configure it to broadcast unless you want to ie. standard way is to -

on the 4507 configure it as an "ntp master" and then on each switch/router configure it as "ntp client "

The ip address can be a loopback or any interface address as long as it is advertised by your routing protocol.

Or did you specifically want to use broadcast ?

Jon

Brent Rockburn · ‎04-08-2010

I just want our servers domain controllers and the like to use the core as the ntp server. So configuring the core as an ntp master is the key?

Jon Marshall · ‎04-08-2010

b.rockburn wrote:

I just want our servers domain controllers and the like to use the core as the ntp server. So configuring the core as an ntp master is the key?

Brent

Yes, but there can be compatability issues between Windows and Cisco, you may need to just test and see what happens. At my last place we had a dedicated time server that we peered a Cisco router to and then peered all our Cisco devices to that router and the Windows guys peered directly with the dedicated time server.

Also are you intending to sync the master 4500 with an internet time server or are you more concerned with just syncing devices to the same time with your LAN ?

Jon

Brent Rockburn · ‎04-08-2010

My 4507 is already synched with external ntp sources.

Jon Marshall · ‎04-08-2010

b.rockburn wrote:

My 4507 is already synched with external ntp sources.

Brent

Great, then you should be all set.

Jon

Jon Marshall · ‎04-08-2010

Brent

Thanks for the ratings but i made a slight error. ntp master is used when there is no external server to sync up with. If you are already syncing to an external device you will have ntp peer commands on your 4507. So you should be able to point other devices to your 4507 already without having to add any other commands on your 4507.

Apologies for that, been a long day

Jon