Synchronisation AIR-AP1232AG-E-K9 with NTP

sysadmin84 · ‎09-23-2005

Hi there,

I'm trying to synchronize my Cisco Access Points (AIR-AP1232AG-E-K9) Clock with our time server (win2k SP2).

In the Web interface of the AP I can only enter an IP address an switch to "enable" but he is not synchronizing. I only get the following message: "Unsynchronized; refresh page occasionally to update the status".

I have not much expirience about NTP und time servers. Only some to enter over the command prompt for synchronizing servers.

I'm hopeless, can anyone help me???

Thanks in advance

Tommy

eddvan · ‎09-23-2005

I'm not a Windows guru, but as far as i know, Win2k

has no real NTP service natively.

Otherwise it should be possible to use following configuration lines to let your APs sync time with an NTP server:

sntp server

or, to make use of NTP broadcasts on your LAN:

sntp broadcast client

Hope this helps

sushilk · ‎09-26-2005

Hi Tommy,

"ntp server ip-address" is the command to be configured on the AP.

I am not aware of WIN2k whether it will act as a ntp server or not.

However if you have an internet connectivity you may one of the available servers here:

http://ntp.isc.org/bin/view/Servers/StratumOneTimeServers

YOu can choose a Open Access server where you will get an IP address of the server. You need to give this IP address in the above command.

You are getting the Unsynchronized error either because the win2K server does not have ntp capability or the AP is not able to cotact the win2k server.

You need to check if there is some access list cofigured on the network which is denying UD traffic.

Since NTP works on UDP port number 123.

A good idea will be to opne this port on the devices.

Hope this helps.

Regards,

Sushil

mirek.tichy_2 · ‎10-06-2005

The NTP does't make problems. The only issue is that the sntp command substituted the ntp comand since 12.3(4)JA relase. Use the sntp server "address" instead of the ntp server "address" (oah, I have forgotten you use the web interface). Try to use some different (public) ntp server too. Check the path to the server.

dopenfield · ‎10-12-2005

We are looking at this same issue as well with using SNTP.

According to what I've found SNTP only allows synchronization with Stratum 1 clocks.

"SNTP time servers should operate only at the root (stratum 1) of the subnet, and then only in configurations where no other source of synchronization other than a reliable radio or modem time service is available. A stratum 2 server cannot be used as an SNTP time server. The use of SNTP rather than NTP in primary servers should be carefully considered. "

I don't understand why this is true. And I don't understand the last sentence in that quote when SNTP is the only option available in the AP. How can we consider not using it when the NTP commands are not available?

Anyone from Cisco have any input about this matter???