Alias address and DHCP

Hi

Before I had a static address to my provider and a alias address on the WAN port.
The alias address is used to be able to reach my ADSL modem.
Now my provider has changed to DHCP and because of that I get a problem
after reboot.
The alias address is active on the interface before the dhcp address and therefor
will become the main address used for outgoing packets. I have to do a renew on
the WAN interface. This will remove the alias address and put just the dhcp address on
the interface. After that I have to manually configure the alias address again.

I have tried to put a alias address in the dhcp.conf but it is cleared after each reboot.

BR
Anders