time synchronization problem on WRT54GS home network: why?
idiotprogrammer
a router problem, a network/isp problem, a bios problem or OS problem.
I have a WRT54GS linksys router, a Windows PC and a thinkpad dual boot
laptop (linux/windows).
Here's the problem: the time on my machines always seems to be 2 hours
off. Yes, I've set and reset the time within the OS, but at some point
it always regresses to the wrong time (usually two hours behind).
Also, I can't remember off the top of my head, but I'm pretty sure the
time in bios on my Windows PC was correct. (I need to verify).
At first, I thought the problem was a WIndows-specific (or maybe a
bios-specific) problem until I found that my 2nd system --a laptop--
was displaying the exact same problem, whether it is in Linux or
Windows. I seem to recall that the event log mentioned some time
problems (which I probably could look up), but the fact that it's
happening on my linux laptop makes me dismiss OS-specific issues. Not
to complicate things unnecessarily, but when I temporarily added
another xp PC a few months ago, it always had the correct time; why is
that?
Please note that my router configuration program (via the web browser)
shows the correct time. Also, aside from setting the time zone, there
is no option that might suggest that it is searching some third party
source for time syncronization.
That leaves two possibilities:
a)my router is causing the synchronization problems
b)maybe there is some ISP related problems, or maybe there is some
problem with whatever time server my router is trying to synchronize
with.
(Actually there is a third possibility: the possibility that my 700 sq
foot apartment is in the middle of a rupture in the space-time
continuum, but I'll leave that aside for now).
In my router, I have the latest bios installed Firmware Version :
v4.70.6 , and the newsgroups and linksys support forums doesn't seem to
have any mention of this kind of problem.
Does anybody have suggestions about how to diagnose/solve this kind of
problem? Am I correct in assuming that the problem MUST be with my
router? If it is a Windows-only problem, why then would the problem be
replicated on my linux-laptop?
Robert Nagle
Houston, Texas
http://www.imaginaryplanet.net/weblogs/idiotprogrammer/
Jeff Liebermann
>Here's the problem: the time on my machines always seems to be 2 hours
>off.
What time zone are you in?
>Yes, I've set and reset the time within the OS, but at some point
>it always regresses to the wrong time (usually two hours behind).
Sounds like you have daylight savings time set in BOTH the BIOS and
the operating system.
>Also, I can't remember off the top of my head, but I'm pretty sure the
>time in bios on my Windows PC was correct. (I need to verify).
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:
http://www.pool.ntp.org
Also, check your "Regional Options" in the Windoze control panel. That
can also mangle the time.
>At first, I thought the problem was a WIndows-specific (or maybe a
>bios-specific) problem until I found that my 2nd system --a laptop--
>was displaying the exact same problem, whether it is in Linux or
>Windows.
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.
>I seem to recall that the event log mentioned some time
>problems (which I probably could look up), but the fact that it's
>happening on my linux laptop makes me dismiss OS-specific issues. Not
>to complicate things unnecessarily, but when I temporarily added
>another xp PC a few months ago, it always had the correct time; why is
>that?
Because it was pointing to time.microsoft.com and not the router.
>Please note that my router configuration program (via the web browser)
>shows the correct time.
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.
>Does anybody have suggestions about how to diagnose/solve this kind of
>problem?
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.
>Am I correct in assuming that the problem MUST be with my
>router? If it is a Windows-only problem, why then would the problem be
>replicated on my linux-laptop?
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.
--
Jeff Liebermann je...@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
idiotprogrammer
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.
Jeff Liebermann
<idiotpr...@gmail.com> wrote:
>Ok, I did a bit more research (probably should have done this before I
>asked the question).
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.
>Turns out the two windows machines were set at pacific time (and I'm on
>central time).
That was step one. Check your assumptions and settings. That which
is most obviously correct, beyond any need of checking, is usually the
problem.
>I know I never did this.
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.
>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).
Troubleshooting NTP:
http://ntp.isc.org/bin/view/Support/TroubleshootingNTP
/etc/ntp.conf is probably not configured or trashed.
>The bios doesn't have any setting for daylight savings, but I notice in
>windows you have that option.
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.
>If you enable this option in the time/date tab on windows, does this
>override the NTP 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.
>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.
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:
http://support.microsoft.com/?kbid=830092
>Thanks for the ideas. That's definitely gotten me started.
--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 je...@comix.santa-cruz.ca.us
# http://802.11junk.com je...@cruzio.com
# http://www.LearnByDestroying.com AE6KS
Rico
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.
Jeff Liebermann
>>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.
>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.
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:
| http://sipx-wiki.calivia.com/index.php/HowTo_Setup_an_NTP_Server_for_Time_Synchronization#Setup_an_NTP_Server_for_Time_Synchronization
Close 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:
| http://wrt-wiki.bsr-clan.de/index.php?title=Startup_Scripts
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:
| http://www.ntp.org/ntpfaq/NTP-a-faq.htm
Chrony allegedly fits and works on WRT54G.
| http://chrony.sunsite.dk
idiotprogrammer
BTW, No, I certainly didn't set the Pacific time zone! Not even by
mistake! It's a windows gremlin.
rj
Mark McIntyre
"idiotprogrammer" <idiotpr...@gmail.com> wrote:
Its the default setting.
--
Mark McIntyre