Multiple IP's on a single interface

[jonkuzma]

This may seem like a silly question but hope someone will be able to answer for clarification. I have inherited a less then stellar network IP Scheme where the second octet is the same as the vlan id. However they started this in the 172. address space so I have things such as 172.111.0.0/16 as a adress range with multiple devices all assigned with static IP's. So my question is can I set a secondary IP address on the same interface currently serving these devices. So that they will continue referencing the gateway of 172.111.0.254 then also have an address of 172.17.0.254 as the new gateway so that as I'm moving things over there will be minimal interference and downtime.

[BenjAudy.MTL]

Hi,

You can put a secondary address on an interface, but make sure you enter the second address without a netmask. You will then have to add a static entry in the corresponding router. Keep in mind that both addresses will be in the same zone (that's probably you wanted anyway).

Benjamin

[santonic]

Yes you can put multiple IP addresses. Just make sure netowrks don't overlap: (hosts can overlap with networks)

So you can have like 192.168.0.100/24, 192.168.0.200/32, 192.168.0.201/32, 10.10.10.100/24, 10.10.10.150/32...

[reaper · Accepted solution]

the secondary IP with /32 is only required if the secondary IP address is inside the primary's subnet

it's perfectly possible to have 2 subnets side by side, as long as there is no overlap: 172.111.0.0/24 and 172.16.0.0/24