Exam 200-301 topic 1 question 213 discussion

The fact that the community is split on this means I am going to have trouble trusting the answers from you all as a whole. The answer is B. Do not believe anything else. If traffic is in a native VLAN it is UNTAGGED, meaning it does not have an assignment. One switch interprets untagged as VLAN 10, the other as VLAN 100, so if untagged so the identification of VLAN is based on location. It will remain untagged where ever it goes but switches will identify it as they have been told.

Answer given correct - SW1 trunk native vlan 10 command will drop the tag from any Vlan 10 traffic and send it out to SW2 without a tag SW2 see's untagged traffic from SW1 and applies it to Native Vlan 100. Earlier question on this site where the answer also states that even though switches will report a Native Vlan mismatch, they will still pass traffic and essentially merge these 2 Vlan's together (unwanted scenario and switch will continue to throw warnings).

I think we misunderstand the question. He is asking how will SW2 handle the traffic from SW1? means that SW2 will receive traffic from SW1 on vlan 10 (native vlan on SW1) ==> as against said that SW2 will send traffic to SW1, if I understand the question correctly. In this case, SW2 will forward the traffic as VLAN 10 because it is tagged with VLAN 10 and allowed on the trunk link between the switches.

there is a native vlan mismatch, so the traffic will be dropped.

its B The traffic will be dropped only if vlan 10 would not be in the allowed vlans! In this case vlan 10 is allowed so SW2 will send the traffic to vlan 100!

Theoretically, under standard conditions, it can be postulated that the traffic generated from Switch-1's native vlan, Vlan-10 will be sent untagged out of its trunk port At the receiving Switch-2's trunk port, this traffic would be directed to the native vlan configured on that port, i.e. Vlan-100 However, that theory discounts the role played by Spanning Tree Protocol in such situations. Spanning Tree Protocol, on detecting the native vlan mis-match on a given trunk link, puts both the mis-matched vlan's at one end of the trunk link, in broken state. The net result is that, traffic from both the mis-matched native VLANs is restricted Rest of the VLANs traffic operates normally https://learningnetwork.cisco.com/s/article/effects-of-mismatched-native-vlans-on-a-trunk-link

In order for PC1 and PC2 to communicate, they must be on the same VLAN, or there must be a router or a layer 3 switch to route the traffic between VLAN 10 and VLAN 100. This process is known as Inter-VLAN routing.

Certainly! When using a trunk between two switches, the native VLAN is considered untagged traffic. The rest of the frames belong to specific VLANs and are tagged to include the VLAN information, allowing them to be forwarded to their destinations1. However, it’s essential to note that the native VLAN must be the same on both sides of the trunk. If it’s not explicitly configured, it defaults to VLAN 1 therefore D is the correct answer

Seems Sw2 would tag the packet for VLAN 100, but then what ? Since the PC is in VLAN 5, and there is nothing in the shown config to say otherwise, the switch should discard the packet.

I think C is correct. Because when two switch are directly connected and connected interface is configured different native VLAN native VLAN mismatch will happen and traffic will be dropped.

B is correct

B its correct

A native VLAN mismatch can cause traffic to be dropped, misrouted, or broadcasted to unintended devices

When there is a native VLAN mismatch, the 2 different native VLANs will merge and form one single broadcast domain.

It´s C. Consulted and tested with CCIE guys

Tested in my LAB. C is the answer.

https://www.ciscopress.com/articles/article.asp?p=2181837&seqNum=9