[CentOS] alias for network on centos 4

I was playing with network alias on centos 4  - i386.

When I activated the alias ifconfig showed the correct eth1:0 information
However I was not able to ping the address.... Tried service network 
stop and start
still not able to ping the address.

After rebooting everything seems to be normal and the alias was available...

Only thing in my alias file was:
IPADDR=x.y.x.y
DEVICE=eth1:0

Is that normal? I would not have thought a reboot would be required for 
that?

Any experiences with alias?

After the reboot, I tried the service network stop and start and 
everything came
up just fine after that. Did not have to reboot...

Thanks,

Jerry