DHCP Questions
Note: If you are not sure about DHCP, please read our DHCP Tutorial.
Question 1
Question 2
Explanation
The command “lease 0 12” set the duration of the lease (the time during which a client computer can use an assigned IP address). The syntax is “lease {days[hours] [minutes] | infinite}”. In this case the lease is (0 day) 12 hours.
We also notice that the pool of IP addresses that can issue to the clients are rather small as the network 192.168.1.0/24 only supports 253 assignable IP addresses. But the first 49 IP addresses were excluded so we only have 253 – 49 = 204 assignable IP addresses < 300 users.
Therefore the best solution is here to reduce the time of each issued IP address (to 2 hours instead of 12 hours) as they only need to use in 2 hours per day, thus increasing the chance of reuse the IP addresses for the clients.
Question 1. For me the right answers are:
C. 802.1X is blocking DHCP traffic
E. The route to the new DHCP server is missing
Reference:
If your device is configured to receive an IP address from a DHCP server but the IP address shown on the client is an Automatic Private IP Addressing (APIPA) address (169.254. x.x) because of autoconfiguration, conclude that the client could not obtain an IP address from the DHCP server. However, do not immediately assume that DHCP is the problem. It is quite possible that you have a Layer 2 problem, such as VLANs, trunks, Spanning Tree Protocol (STP), or security, that is, for example, preventing the client’s DHCPDISCOVER message from reaching the DHCP server.
Lacoste, Raymond; Edgeworth, Bradley. CCNP Enterprise Advanced Routing ENARSI 300-410 Official Cert Guide (Kindle Locations 1285-1289). Pearson Education. Kindle Edition.
Hi admin, as seen in the post by Heamgu, is his answers correct? Thank you.
@Heamgu, @Question_Heamgu: This question did not mention anything about 802.1X so we are not sure if 802.1X is using in the corporation. So answer B & E are still better.
I agree with the admin, B & E are the closest match due to the below reason from my point of view (could be wrong):
Heamgu perspective might be correct in case of the users devices were physically connected to new switchports which will require 801.X authentication, however this doesn’t seem to be the case.
The case here is that the ip address of the DHCP server was changed from A to B while keeping the users physically connected to the SAME switch ports. So this is probably a totally new subnet with a probably a different pool of IP’s and also the users don’t know how to reach it.
That’s why I vote B & E are the most accurate answers.
Question 1 is the same of old route exam dumps (300-101). How is possible
@networktut,
on the question: Refer to the exhibit. Users report that IP addresses cannot be acquired from the DHCP server. The DHCP server is configured as shown. About 300 total nonconcurrent users are using this DHCP server, but none of them are active for more than two hours per day.
Which action fixes the issue within the current resources?
A. Configure the DHCP lease time to a bigger value
B. Add the network 192.168.2.0 255.255.255.0 command to the DHCP pool
C. Modify the subnet mask to the network 192.168.1.0 255.255.254.0 command in the DHCP pool
D. Configure the DHCP lease time to a smaller value
The best response is C. In fact, if we change the mask, to 255.255.254.0, we can have more than 300 IP to use. This answer is better than D. D is random. All users can be connected at the same time, even though they are connected for only 2h.
Can you please check?
@Maxio: This question clearly states “none of them are active for more than two hours per day” so we should reduce DHCP lease time to save addresses.
What if all 300 users are online between 10 and 11 (rush hour in university) every day ?
I think C is better.
@Borste, Q2 says “nonconcurrent” meaning not at the same time.
For question 2, C cannot be the correct answer.
As this command network 192.168.1.0 255.255.254.0 will not be valid. it will be only valid if it is network 192.168.0.0 255.255.254.0