You have the following configuration on your router:
ip dhcp pool POOLNAME
network 10.1.0.0 255.255.255.0
default-router 10.1.0.254
dns-server 10.1.0.200
What command would you run to prevent the last available IP address in the scope from being allocated to a host via DHCP?
A. ip dhcp restrict 10.1.0.254
B. ip dhcp excluded-address 10.1.0.253
C. ip dhcp excluded-address 10.1.0.254
D. ip dhcp 10.1.0.253 excluded-address
Correct Answer: B
Explanation:
In this scenario, you would run the ip dhcp excluded-address 10.1.0.253 command in global configuration mode to prevent DHCP allocation of the last available IP address in the scope. The ip dhcp excluded-address command is used to prevent DHCP from handing out IP addresses that are already statically configured on your network. The command can include a single IP address to exclude, or an entire range, such as:
Router(config)# ip dhcp excluded-address 10.1.0.100 10.1.0.125
The command above would block the entire range of 10.1.0.100 through 10.1.0.125 from being allocated by DHCP. If the next IP address in sequence to be assigned would have been 10.1.0.100, DHCP will skip the range and assign 10.1.0.126 as the next host address.
You would not execute ip dhcp excluded-address 10.1.0.254. This is the address of the router and it will automatically be excluded. The other commands are incorrect because they are not valid Cisco IOS commands.