Home » Cisco » 200-105 » Which two circumstances can cause collision domain issues on VLAN domain?
Which two circumstances can cause collision domain issues on VLAN domain? (Choose two.)
A. duplex mismatches on Ethernet segments in the same VLAN
B. multiple errors on switchport interfaces
C. congestion on the switch inband path
D. a failing NIC in an end device
E. an overloaded shared segment
Answer: AC
Explanation:
Collision Domains
A collision domain is an area of a single LAN where end stations contend for access to the network because all end stations are connected to a shared physical medium. If two connected devices transmit onto the media at the same time, a collision occurs. When a collision occurs, a JAM signal is sent on the network, indicating that a collision has occurred and that devices should ignore any fragmented data associated with the collision. Both sending devices back off sending their data for a random amount and then try again if the medium is free for transmission.
Therefore, collisions effectively delay transmission of data, lowering the effective throughput available to a device. The more devices that are attached to a collision domain, the greater the chances of collisions; this results in lower bandwidth and performance for each device attached to the collision domain. Bridges and switches terminate the physical signal path of a collision domain, allowing you to segment separate collision domains, breaking them up into multiple smaller pieces to provide more bandwidth per user within the new collision domains formed.
Found this on anther site…
1- Duplex mismatches on Ethernet segments in the same VLAN
2- A failing NIC in an end devices
Collision domain is defined as connected devices configured in a half-duplex port configuration, connected to each other or a hub. If a device is connected to a switch port and full-duplex mode is configured, such a point-to-point connection is collisionless. Slowness on such a segment still can occur for different reasons.
Slow Broadcast Domain Connectivity (Slow VLAN)
Slow broadcast domain connectivity occurs when the whole VLAN (that is, all devices on the same VLAN) experiences slowness.
Slow InterVLAN Connectivity (Slow Forwarding Between VLANs)
Slow interVLAN connectivity (slow forwarding between VLANs) occurs when there is no slowness on the local VLAN, but traffic needs to be forwarded to an alternate VLAN, and it is not forwarded at the expected rate.
not tricky… just more confusion from Cisco…
keep it in perspective, a collision domain is usually a switch port and a workstation…. the vlan is consider a broadcast domain… hubs are NOT used today…
A. duplex mismatches on Ethernet segments in the same VLAN – will definitely cause collisions
B. multiple errors on switchport interfaces – dependent on the type of errors, but probably
C. congestion on the switch inband path – dependent on the amount of congestion – packet loss is definitely any issue..what do they mean by “inband” ingress or inband mgmt?? then say ingress… just confusion
D. a failing NIC in an end device – dependent on whats failing, encap issues? fragmented packets, jumbo frames, runts…is it hw or sw issue? who knows
E. an overloaded shared segment – how overloaded? packet loss, collisions, tx or rx
how can you answer a question, when they dont know what their asking??
I think the question is very tricky: https://www.cisco.com/c/en/us/support/docs/lan-switching/virtual-lans-vlan-trunking-protocol-vlans-vtp/23637-slow-int-vlan-connect.html
I agree with Rusian
Cisco way
Why “D” is not correct…???
Failing NIC in an end device can also send frames , when is when it is not needed… and collison will be created….