I inherited quite a network in terms of centralized or correct configuration. The prior administrators did not configure many basic services correctly and myself and my Senior Administrator are now being hammered with several problems they left behind.

One of the issues we are seeing now is a problem with the time being off, incorrect, or inconsistent across the network. The prior team left us with no documentation so we dug through the switch configs and ran some basic NTP and time checking commands on the switches and came to the conclusion NTP and propper times were just ignored entirely (Many of our switches think its 1992/1993, some midnight, some 3:30 in the afternoon.)

I'm going through the process of having a master time source set aside and am currently writing the configs for our Cisco switches so they can pass the configs on to about 350 Wyse thin clients across each location through the DHCP service they run. Many times these units will be picked up and carried to a new location (Sometimes without us even knowing) and there is pressure to make it all "Just work" from top management.

My question:

I'm applying option 42 to the DHCP pools to point to our master time source so we can get the NTP server to each of the WYSE units. I have seen mixed reports about if I should use option 2 (The offset) Source of concerns and if so If so how do i account for Daylight Savings Time in the configs.

I found a page about Cisco Offsets so i think I can pick the right one.

The real issue for me is making sure we do not have issues with the DST as it has already caused us more pain then we would like to repeat. What is the recommended way of handling this?


After a bit more searching and testing I was able to get a solution that worked for me, not sure if this is the best solution but it worked.

I created several copies of the configuration files and placed them in a sub directory of the FTP root directory on my WDM (Wyse Device Manager) server.

I named each one after a different time zone and set all the correct information (NTP Server, DST start/end, Timezone) into these files.

I then used option 162 (FTP Home Directory) on each Cisco switch to point the WYSE units to a timezone specific version of the configs.

Following that I enabled a NTP server on each Cisco switch and pointed them to the master here in the data center and also added the NTP server option to DHCP pools so any devices that look there could pick them up.

As of now devices connecting to an EST network get the correct EDT timezone and those connecting to a CST network get the correct CDT timezone.

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