Using the default bridge, I have set up a couple of VMs that I need to access using their hostnames (provided by the router). If the VMs start after the router, everything works perfectly. Their hostname is used to setup a LAN domain and the router happily resolves it to its current IP address (e.g. my-test-vm and my-test-vm.localdomain both resolve to 192.168.5.143).
If, for any reason, the router restarts and loses its leases, the domains hosts fail to resolve. This (I believe) happens because the Unraid bridge stays up and doesn't follow the state of the host's NIC. If the bridge reported that the link has dropped, the VMs would renew their leases automatically.
I know this can be solved in numerous other ways, by setting static leases on the router, by persisting the DHCP lease to permanent storage, etc