You can increase fault tolerance by splitting DHCP scopes between multiple DHCP servers. With a split-scope configuration, ...

You can increase fault tolerance by splitting DHCP scopes between multiple DHCP servers. With a split-scope configuration, if one DHCP server becomes unavailable, the other server can take its place and continue to lease new IP addresses or renew existing leases. Splitting DHCP scopes also helps to balance server loads.