Hwclock does not maintain correct time

[ScottLClement]

I have a DL580 itanium server running redhat linux RHEL 4. THe hardware clock floats drastically. After 19 days of uptime it was 2days + behind. Does anyone have any ideas why this is?

[Ivan Ferreira]

Hello, please see this thread and try the suggestions there.

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=999210

[Steven E. Protter]

Shalom,

Congratulations, you have discovered that computers can't tell time.

I would suggest you set up ntp and ignore the hardware clock.

If its really interfering with system operation and ntp can't sync it, have the system board replaced. Your results are pretty bad but I've seen worse.

SEP

[ScottLClement]

We have set up ntp but we are having problems getting out the correct nic to hit the outside time server. We have 3 nics on 3 different subnets and it fails to get out yet from telnet window we can ping and nslookup the time server just fine.

[Morten Lange]

Hi,

Regarding connectivity to the NTP server, you should know that NTP uses port 123 udp _and_ tcp.

When you say telnet, are you telnetting to port 123 on the ntp server ?
To test 123 udp I think you could use nmap.
Is there a firewall on the route between the to boxes or perhaps iptables or something running on your linux box ?

Then there is the question of whether you are going out through the right NIC. Have you double-checked the routing tables ?

Best Regards,
Morten

[George Liu_4]

1. firewall to allow tcp/udp 123 on both
sides
2. modify ntp.conf, and step-tickers
3. restart ntpd
that's it