Hello,

I have two laptops side by side, one running SL6, the other SL7, both up 
to date.  According to the date command, their times agree to within a 
small fraction of a second.

On both machines, I normally run kinit to get a kerberos ticket in the 
same realm.  Today, the SL7 machine gets its ticket normally, but the 
SL6 one shows an error message "Clock skew too great while getting 
initial credentials".  Since the clocks of the two machines appear to 
agree, I would have expected that either both should produce the error 
or neither.  From what I have read on the web, the standard tolerance 
for clock skew is 5 minutes, and the agreement between the times on the 
two machines is well within that.

Both machines have ntpd running, using the time servers 
[0-3].rhel.pool.ntp.org.  Powering off the SL6 machine and rebooting 
does not restore sanity.  The problem just arose today.  There have been 
no system updates on the SL6 machine since it successfully got its 
ticket yesterday.

Any suggestions for what to try?

Stephen Isard