change subnet mask floating self ip

hi,

 

i'm trying to change the subnet mask on a self floating ip

 

172.19.102.1 172.19.102.1%4 255.255.255.240 extstaging_webcontent traffic-group-1 ExtStaging 172.19.102.13 172.19.102.13%4 255.255.255.240 extstaging_webcontent traffic-group-local-only ExtStaging

 

when i change either subnet of the ip's above i get the error below:

 

01070601:3: A self IP matching the old network / mask 172.19.102.0%4 / 255.255.255.240 still exists in the configuration

 

kr Dimitri