Exam JN0-351 All QuestionsBrowse all questions from this exam
Question 53

You have DHCP snooping enabled but no entries are automatically created in the snooping database for an interface on your EX Series switch.

What are two reasons for the problem? (Choose two.)

    Correct Answer: A, C

    Entries in the DHCP snooping database are created only when a device goes through the DHCP process to obtain an IP address. If the device connected to the interface has performed a DHCPRELEASE, it releases the IP address and the entry gets removed from the database. Additionally, if the device connected to the interface has a static IP address, it will not go through the DHCP process and thus no entry will be created in the DHCP snooping database.

Discussion
infravmwareOptions: AC

When a network device releases an IP address (sends a DHCPRELEASE message). In this event, the associated mapping entry is deleted from the database.

sandaruwann654Options: AC

A,C are correct

oz1iOptions: AC

AC is correct

lmla89Options: BC

MAC limiting: If MAC limiting is enabled on the interface, it could potentially interfere with the operation of DHCP snooping.MAC limiting restricts the number of MAC addresses that can be learned on a physical interface to prevent MAC flooding attacks1. This could inadvertently limit the number of DHCP clients that can be learned on an interface, thus preventing new entries from being added to the DHCP snooping database. Static IP address: If the device connected to the interface is configured with a static IP address, it will not go through the DHCP process and therefore will not have an entry in the DHCP snooping database1.The DHCP snooping feature relies on monitoring DHCP messages to build its database1, so devices with static IP addresses that do not send DHCP messages will not have their information added.