time synchronization problem on WRT54GS home network: why?

"idiotprogrammer" hath wroth:

What time zone are you in?

Sounds like you have daylight savings time set in BOTH the BIOS and the operating system.

It doesn't matter for Windoze XP. It has a built in NTP client that queries time.microsoft.com. This is not the most reliable time server on the planet. You might want to change it to something in the NTP server pool at:

Also, check your "Regional Options" in the Windoze control panel. That can also mangle the time.

Hmmm... Do you have both the Linux and Windoze boxes pointing to the WRT54G as an NTP server? I don't think the stock Linksys firmware supports an NTP server, although the alternative firmware certainly does.

Because it was pointing to time.microsoft.com and not the router.

Careful here. What the router displays and what NTP delivers may be quite different depending on TZ settings. Most often, it delivers UTC, and the client compensates for time zones and daylight savings time.

The usual troubleshooting proceedures:

1. Check your assumptions.
2. Check your settings.
3. Read the log files.
4. If all else fails, reset to defaults and start over.

Assumption is the mother of all screwups. No, it's not necessarily your router. It can be multiple problems including your choice of TZ string, daylight savings time settings, BIOS time settings, Region Options, NTP server, etc. Point your clients at a real NTP server, don't use the NTP server in the router if offered, and live happily ever after.

Ok, I did a bit more research (probably should have done this before I asked the question).

Turns out the two windows machines were set at pacific time (and I'm on central time).

I know I never did this. I selected the option to synchronize with a non-MS server and update now. That seemed to fix it. Not sure why it reverted to pacific time, unless it was reverting to local settings when it couldn't access the time server.

On the linux laptop, i told it to look for a time-server, and that fixed it. (Update: NO, it did not. I fixed it on a onetime basis, but the service failed at start up).

So I'm good for now.

The bios doesn't have any setting for daylight savings, but I notice in windows you have that option.

If you enable this option in the time/date tab on windows, does this override the NTP time?

Another question which I should look into is whether the linksys router is blocking these synchronization checks. Not sure whether I need to open a port for that.

Thanks for the ideas. That's definitely gotten me started.

Robert Nagle Houston, Texas

Naw. It's more fun to beat your head against the wall for hours before doing some reading. Besides, it's bad form to admit that you need to read the manual.

That was step one. Check your assumptions and settings. That which is most obviously correct, beyond any need of checking, is usually the problem.

Ummm... right. Setting just change by themselves. If you suspect your computer is haunted or infested with setting changing poltergeists, perhaps an exhorism will help.

Troubleshooting NTP:

is probably not configured or trashed.

Some do, some don't. I usually leave the BIOS daylight settings time off and let the OS deal with daylight savings time. I got a bit tired of finding my clock change by 2 hours instead of one when both the bios and the OS jugggle the time.

XP seems smart enought to deal with it. The default setup is to have the "Automatically adjust clock for daylight savings changes" box checked.

Port 123 is the required port. Unless you're running a public time server, you don't need to do any tweaking for outgoing ports. As usual, Microsoft has bugs. See:

It does? How do you enable it? I want to make my router my time source for my network in the 'worst' sort of way but have been unable to do it. DD-WRT seems to only have the client demon, not the server installed.

Well I disagree, once you have a single source on the network getting the correct time (like the router) will keep your 'extra' computers from adding to the traffic load on the ntp server you select. Ask it once with one computer and share the results with the others...

fundamentalism, fundamentally wrong.

If it has ntpd, it has an NTP server. You'll find it as /sbin/ntpd along with /etc/ntpd.conf as the configuration file.

I've never tried to setup mine as an NTP relay server. I may need to do that soon because I have a customer with a mess of SIP phones that wants to keep the log files in sync without relying on any connections between the clients and the interknot. The phones have no real time clock so they need to get the time from somewhere. So, I need a local NTP server.

How to setup an NTP server with Linux: |

but not the same as the DD-WRT setup. I couldn't find anything on the DD-WRT wiki. Looks simple enough. I'll probably have to start ntpd with a script: | I don't really want to mess with the configuration on my office WRT54G, but I have a spare WRT54G that should work. Maybe later in the week.

FAQ: |

Chrony allegedly fits and works on WRT54G. |

Jeff, thanks for your help.

BTW, No, I certainly didn't set the Pacific time zone! Not even by mistake! It's a windows gremlin.

rj

Its the default setting.