Many have pointed out that a VLAN can hold one or more subnets. If your default gateway for this subnet is on a router or a L3 switch then how could there be more than one default gateway in a VLAN configuration? On a router you map each subinterface to a VLAN and give it an IP and you can't have two subinterfaces with the same VLAN. On a L3 switch you give the VLAN interface an IP and that acts as the default gateway; you can't give it two IPs. So, how would one go about including two subnets in one VLAN?
You can use secondary addressing to add another subnet onto a SVI, this is not recommended but can be used if you really need it.
Current configuration : 190 bytes ! interface Vlan45 ip address 18.104.22.168 255.255.255.0 secondary ip address 22.214.171.124 255.255.255.0 secondary ip address 126.96.36.199 255.255.255.0 secondary ip address 188.8.131.52 255.255.255.0 end