ECMP agreement in the presence of multiple most path will be based on hash algorithm for load balancing, online figure is as follows:


Suppose I topology is as follows, a switch has multiple optimal path server:


So when I dropped a server down, according to the above said, the method of modulus of the hash of the cluster structure is wrong, I s0down off, then had to go to s1 flow may not continue to hash to s1, is that so?
If is, whether the hash algorithm is a problem? In a different protocol implementation of ecmp algorithm whether there will be differences in this respect? Ospf protocol supported in ecmp is what kind of the hash algorithm?
If not, whether to have the standards?

Thank you in advance