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NTP problems on 877W Router

CliffGrover
Level 1
Level 1

To log some problems I want to ensure the router date & time is up to date after reboots.

I have added NTP servers (initially 2 - a preferred and a non-preferred, but in the end a total of 5 attempts) using SDM, which also created the necessary firewall rules.  However, subsequently the configured NTP servers did not remain on the NTP server list under the relevant SDM page (i.e. the list area is completely blank). I have added servers by both IP address and name. I saved the running config to the start-up config in each case, using SDM

On listing the full router config text file, only one of the first 4 additions was listed, plus the most recent one added. The two listed were both "preferred", so deleted the older one (under IOS as neither was not showing on the SDM page).

Additionally, the SDM Date/Time page shows "Router Time Source" as NTP, however, the time in the status bar indicates "PCTime" (I did sync with the PC after the recent reboots in order to rapidly force an up to date time)

I have looked around the Cisco support site and believe I may have tripped over an issue around NTP servers?

Can anyone give me any advice on how to configure this correctly? Also, how can I force the modem to update from the NTP server immediately after a reboot.

Router: 877W  IOS version: 12.4(20)T   SDM version : 2.5

TIA

Cliff

1 Accepted Solution

Accepted Solutions

Ganesh Hariharan
VIP Alumni
VIP Alumni

To log some problems I want to ensure the router date & time is up to date after reboots.

I have added NTP servers (initially 2 - a preferred and a non-preferred, but in the end a total of 5 attempts) using SDM, which also created the necessary firewall rules.  However, subsequently the configured NTP servers did not remain on the NTP server list under the relevant SDM page (i.e. the list area is completely blank). I have added servers by both IP address and name. I saved the running config to the start-up config in each case, using SDM

On listing the full router config text file, only one of the first 4 additions was listed, plus the most recent one added. The two listed were both "preferred", so deleted the older one (under IOS as neither was not showing on the SDM page).

Additionally, the SDM Date/Time page shows "Router Time Source" as NTP, however, the time in the status bar indicates "PCTime" (I did sync with the PC after the recent reboots in order to rapidly force an up to date time)

I have looked around the Cisco support site and believe I may have tripped over an issue around NTP servers?

Can anyone give me any advice on how to configure this correctly? Also, how can I force the modem to update from the NTP server immediately after a reboot.

Router: 877W  IOS version: 12.4(20)T   SDM version : 2.5

TIA

Cliff

Hi Cliff,

Configuration of NTP is simple via CLI just take a session for router via telnet or console and configure the following configuration for ntp.

Enter the following commands

Router# configure terminal
Router(config)# ntp server

Router# copy runn star-up then press enter

Please also Note once you have configured NTP check the NTP status and Association with ntp server by issuing the following commands

show ntp status

show ntp association

*  NTP is a slow protocol, and the formation of NTP associations can take a long time. So, don't expect anything to happen fast.
* If you decide to use an Internet NTP server, make sure you open UDP port 123 inbound on your firewall to your NTP client.

HTH

Ganesh.H

View solution in original post

4 Replies 4

Giuseppe Larosa
Hall of Fame
Hall of Fame

Hello Cliff,

get a telnet access to the router and use

sh ntp status

sh ntp association

sh run | inc ntp

I don't use SDM but configuration of NTP on CLI is not very difficult.

Also it may be time to start to access directly the router you may be facing a problem that is an SDM problem or even only a question of wrong presentation of information.

feel free to post the outputs of the above commands in the forum to get better help

Hope to help

Giuseppe

Ganesh Hariharan
VIP Alumni
VIP Alumni

To log some problems I want to ensure the router date & time is up to date after reboots.

I have added NTP servers (initially 2 - a preferred and a non-preferred, but in the end a total of 5 attempts) using SDM, which also created the necessary firewall rules.  However, subsequently the configured NTP servers did not remain on the NTP server list under the relevant SDM page (i.e. the list area is completely blank). I have added servers by both IP address and name. I saved the running config to the start-up config in each case, using SDM

On listing the full router config text file, only one of the first 4 additions was listed, plus the most recent one added. The two listed were both "preferred", so deleted the older one (under IOS as neither was not showing on the SDM page).

Additionally, the SDM Date/Time page shows "Router Time Source" as NTP, however, the time in the status bar indicates "PCTime" (I did sync with the PC after the recent reboots in order to rapidly force an up to date time)

I have looked around the Cisco support site and believe I may have tripped over an issue around NTP servers?

Can anyone give me any advice on how to configure this correctly? Also, how can I force the modem to update from the NTP server immediately after a reboot.

Router: 877W  IOS version: 12.4(20)T   SDM version : 2.5

TIA

Cliff

Hi Cliff,

Configuration of NTP is simple via CLI just take a session for router via telnet or console and configure the following configuration for ntp.

Enter the following commands

Router# configure terminal
Router(config)# ntp server

Router# copy runn star-up then press enter

Please also Note once you have configured NTP check the NTP status and Association with ntp server by issuing the following commands

show ntp status

show ntp association

*  NTP is a slow protocol, and the formation of NTP associations can take a long time. So, don't expect anything to happen fast.
* If you decide to use an Internet NTP server, make sure you open UDP port 123 inbound on your firewall to your NTP client.

HTH

Ganesh.H

Thanks Giuseppe and Ganesh; I'll give that a go.

Is there no way to force a time update on router start?

The command "clock initialize" initializes system clock on restart.  This command is supported on the 870 series.  I'd also think about using the command "clock save interval <8-24 hours>".

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