In the image below i run quagga ospfd daemons as routers in picture. I want to add 1+1 redundancy to 172.16.1.0 network this way: if 172.16.1.1 became unavailable 172.16.1.128 changes its IP address to 172.16.1.1 assigns relevant IP addresses to its interfaces and replace the now unavailable router. This process requires ospf to learn topology and converge in the new board and make network disconnected for some while. So i need a way to sync ospfd on 172.16.1.1 with ospfd on 172.16.1.128.
There's really no need to change the IP address of the device, as long as your devices support VRRP (since it is linux based, it does)
Give to both devices an address within 172.16.1.0/24 (like .2 and .3) and set 172.16.1.1 as a virtual address with VRRP
Then configure OSPF on all devices, setting the cost so the primary router will be preferred over the backup one.