Looking to know if a secondary address will automatically become the primary if a primary address also configured on a FastEthernet LAN port is removed, or will it be removed as well?
ip address 10.24.216.1 255.255.248.0 secondary
no ip address 10.40.80.1 255.255.248.0
The primary can't be removed unless all the secondaries are removed first. If you try to remove the primary, you will get the following message:
R1(config-if)#no ip address 192.168.1.1 255.255.255.0
Must delete secondary before deleting primary
Hope this helps,