Measure the test taker's knowledge about how to add DHCP super scopes.

In the previous article, we have introduced how to add a DHCP scope. I don't know if you still remember it. Here we will focus on the process of adding a DHCP super scope. If you need to set up a DHCP server in each subnet of the LAN, you must use a super scope.

Because each DHCP client needs to send the DHCPdiscover message in the subnet in the form of limited broadcast at the initial start, if there are multiple DHCP server users in the network, it is unpredictable that the server responds to the client request.

Assume that there are two servers on the network:

Server 1 and Server 2 provide different address ranges. If Server 1 is used by the client through address lease, when the lease period reaches 50%, the client needs to communicate with Server 1 to update the lease, if you cannot communicate with Server 1, when the lease term reaches 87.5%, the client enters the re-application status, and the client sends a broadcast on the subnet. If Server 2 responds first, because Server 2 provides different IP address ranges, it does not know that the client is currently using a valid IP address, so it will send DHCPNAK (negative acknowledgement) to the client, the client cannot obtain a valid address lease. This may also happen when Server 1 is active.

Therefore, you need to configure a super scope on each server to prevent the above problems. The super scope should include all valid IP address ranges in the subnet as its member ranges, and set the IP ranges provided by other servers in the subnet to exclude IP ranges when setting the member ranges.

Add DHCP super scope Step 1 click server → operate super scope → fill in super scope domain name → select the scope to be added to super scope → complete

Add DHCP super scope Step 2 set the address range of other scopes to exclude in the address pool of each scope