Exam 200-301 topic 1 question 577 discussion

I think its STP, specifically portfast. I found this one the cisco white pages, under the DHCP troubleshooting section. "...verify that the port has STP portfast enabled and trunking/channeling disabled. The default configuration is STP portfast disabled and trunking/channeling auto, if applicable. For the 2900XL/3500XL/2950/3550 switches, STP portfast is the only required configuration. These configuration changes resolve the most common DHCP client issues that occur with an initial installation of a Catalyst switch." from https://www.cisco.com/c/en/us/support/docs/ip/dynamic-address-allocation-resolution/27470-100.html#anc72

The time it takes to get to the Forwarding state might be too long for a client's DHCP process (which starts after the interface on the client becomes 'up'). Using Spanning-Tree PortFast can mitigate this exact issue. So yes, STP can prevent workstations from getting an IP-adress using DHCP.

Correct Answer: STP STP can prevent DHCP clients from getting an IP address because the port doesn't start forwarding traffic until STP goes into the forwarding state.

The correct answer is D. DTP (Dynamic Trunking Protocol). DTP (Dynamic Trunking Protocol) is a Cisco proprietary protocol used to negotiate trunking between switches. It operates on trunk ports and helps switches dynamically determine whether to form a trunk link with another switch. The other options (STP, VTP, and 802.1Q) are not directly related to DHCP address assignment:

A. STP (Spanning Tree Protocol) Spanning Tree Protocol (STP) can potentially prevent a workstation from receiving a DHCP address if it blocks or disables the port through which DHCP requests are transmitted. STP operates at Layer 2 of the OSI model and is responsible for preventing loops in network topologies by blocking redundant links. If a port is in a blocking state due to STP convergence or a topology change, DHCP requests sent from workstations connected to that port may not reach the DHCP server, resulting in the inability to obtain an IP address dynamically.

A is correct

So guys, under no circumstances does STP prevent a host from receiving DHCP. Let's imagine the following scenario: We have 1 L3 switch, and in this switch we have a DHCP server configured in VLAN 10, if the host port is in the default VLAN, this equipment will not receive an address from that DHCP, on the other hand, if its interface is in VLAN 10, it will receive the address, therefore the correct answer is C.

the same question was answered "STP" in question 108 https://www.examtopics.com/discussions/cisco/view/14022-exam-200-105-topic-2-question-108-discussion/

In this context, the correct option is C. 802.1Q. The reason is that 802.1Q is a VLAN tagging standard used to transport traffic for multiple VLANs over a trunk link. If a port is configured as a trunk (802.1Q), and the workstation is not configured to tag its traffic with the correct VLAN, the workstation might face difficulties in receiving an IP address via DHCP.

STP can prevent DHCP clients from getting an address because the port doesn't start forwarding traffic until STP goes into the forwarding state. That can be up to 30 seconds. By then the client has timed out. Cisco has a command called "portfast" to fix this.

The correct answer is C. 802.1Q. Explanation: A. STP (Spanning Tree Protocol): STP is a protocol that prevents loops in a network by blocking redundant paths. It does not prevent a workstation from receiving a DHCP address. B. VTP (VLAN Trunking Protocol): VTP is used for managing VLAN configurations in a network. It does not prevent a workstation from receiving a DHCP address. C. 802.1Q: This is a standard for frame tagging in VLANs. If a switch port is configured as an 802.1Q trunk port and the workstation is not configured to handle VLAN tagging, the workstation may not be able to receive a DHCP address because it is not on the correct VLAN. D. DTP (Dynamic Trunking Protocol): DTP is a Cisco proprietary protocol used to negotiate trunking between switches. It does not prevent a workstation from receiving a DHCP address. In summary, 802.1Q, which deals with VLAN tagging, is the most relevant option when considering issues related to a workstation not receiving a DHCP address in a VLAN environment.

The options provided (STP, VTP, 802.1Q, DTP) are not directly related to preventing a workstation from receiving a DHCP address. Therefore, none of the given options are the correct answer in the context of DHCP issues. It's important to troubleshoot DHCP problems by checking network connectivity, DHCP server availability, and proper configuration.

Ok, how about C? If the port is in access mode, on vlan X and DHCP on vlan Y, and there's no dhcp relay configured, it'll prevent the computer to get IP.

STP will prevent a workstation from receiving a dhcp message

STP is the best option because when the port is blocked the client will not receive a dhcp address hence apipa will be used

in such questions the best practise is to exclude the wrong asnwers first. VTP - says how to spread out VLANs across the network between sw - this one is out. DTP - says how to create a working trunk. btw on trunk int you won't get an dhcp - ip, so this one out as well. 802.1q - says how to tag VLAN-id in trunk - so also this one is out. so just with exclusions the last option is STP, which after reading the explanatory comments make sense. So A is definitely correct.

this is a very stupid question, I hope not to see such garbage on the exam especially for ccna level.