What if one host is defined in /etc/hosts like:192.168.0.100   serverand one is defined in ~/.ssh/config like: Host    server         HostName    192.168.0.101and you ssh into server: ssh server.How would such a conflict be resolved? I guess one has higher priority than the other.
What will be prioritized in a conflict between ~/.ssh/config hostname and /etc/hosts?
ssh;hostname;hosts
If you do ssh server the server part could be a real host name or some ssh internal nickname. ssh first looks for some nickname in .ssh/config, if it finds a configuration there it will use this. If it does not find a configuration it assumes a real hostname and tries to resolve it via /etc/host and dns.