ip alias disappear periodically

Hi, I had ip alias (eth0:1) setup on fedora 3 (minimun package setup).
The ip alias (eth0:1) disppeared every 1 or 2 days while the main
interface (eth0) is still up.

If I ran ifup eth0a ( I saved the ip alias setting as
/etc/sysconfig/network-scripts/ifcfg-eth0a ) after it went down, it
worked fine for 1 or 2 days.

I checked daemon netplugd and
/usr/sbin/acpid, they are not running.

I checked /etc/cron.*. Only normal stuff are there:

lrwxrwxrwx 1 root root 28 Dec 16 22:40 00-logwatch ->
.../log.d/scripts/logwatch.pl
-rwxr-xr-x 1 root root 276 Sep 28 10:16 0anacron
-rwxr-xr-x 1 root root 180 Oct 19 14:57 logrotate
-rwxr-xr-x 1 root root 1619 Sep 9 03:43 prelink
-rwxr-xr-x 1 root root 104 Nov 1 18:54 rpm
-rwxr-xr-x 1 root root 286 Aug 13 16:42 tmpwatch

I renamed
/sbin/ifdown
/etc/sysconfig/network-scripts/ifdown
/etc/sysconfig/network-scripts/ifdown-aliases
in case some server/process call them. But the ip alias still went down
after a while.

So when can cause ip alias go down or disappear ?
Thanks a lot.


- John