Cisco CCNA mock exam questions sample test – Question 176

.In which two situations would it be appropriate to issue the ipconfig command with the /release and /renew options? (Choose two.)

A. When the result of running the ipconfig /all command indicates a 169.254.163.6 address
B. When recent scope changes have been made on the DHCP server
C. When no IP helper address has been configured on the router between the client and the DHCP server
D. When the no ip directed-broadcast command has been issued in the router interface local to the client, and no IP helper address has been configured on the router between the
client and the DHCP server

Correct Answer: AB

Explanation:
It would it be appropriate to issue the ipconfig command with the /release and /renew options when the result of running the ipconfig /all command indicates a 169.254.163.6 address,
or when recent scope changes have been made on the DHCP server. When a computer has an address in the 169.254.0.0 network, it indicates that the computer has not been
issued an address from the DHCP server. Instead, the computer has utilized Automatic Private IP Addressing (APIPA) to issue itself an address. If the reason for this assignment is a
temporary problem with the DHCP server or some other transitory network problem, issuing the ipconfig /release command followed by the ipconfig /renew command could allow the
computer to receive the address from the DHCP sever.
Similarly, if changes have been made to the settings on the DHCP server, such as a change in the scope options (such as gateway or DNS server), issuing this pair of commands
would update the DHCP client with the new settings when his address is renewed.
These commands will have no effect when no IP helper address has been configured on the router between the client and the DHCP server. An IP helper address can be configured
on the local interface of a router when no DHCP server exists on that subnet and you would like to allow the router to forward DHCP DISCOVER packets to the DHCP server on a
remote subnet. DHCP DISCOVER packets are broadcast, and routers do not pass on broadcast traffic by default.
These commands also will be of no benefit if the no ip directed-broadcast command has been issued in the router interface local to the client and no IP helper address has been
configured on the router between the client and the DHCP server. The no ip directed-broadcast command instructs the router to deny broadcast traffic (which is the default). Under
those conditions, the command will not result in finding the DHCP server or receiving an address.
Objective:
Infrastructure Services
Sub-Objective:
Troubleshoot client- and router-based DHCP connectivity issues