Secondary Addresses

[kennethsali]

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?

!

interface FastEthernet0/0

ip address 10.24.216.1 255.255.248.0 secondary

no ip address 10.40.80.1 255.255.248.0

[Harold Ritter · Accepted solution]

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

R1(config-if)#

Hope this helps,

[ceo4eva]

When you have a secondary IP and you want to make it the primary, just use the ip address command without secondary and it will make it the primary while getting rid of it as the secondary.

[Nikolaos1313]

ok but what about the primary one? what will happen to it? also will i lose connectivity or no?