A network architect decides to expand the scope of the multicast deployment within the company network. The network is already using PIM-SM with a static RP that supports a high-bandwidth, video-based training application that is heavily used by the employees, but excessive bandwidth usage is a concern. How must the engineer update the network to provide a more efficient multicast implementation?
The question primarily addresses the need to mitigate excessive bandwidth usage in a multicast deployment using PIM-SM with a static RP. Configuring IGMP (Internet Group Management Protocol) on each LAN to manage multicast hosts is an effective way to control and reduce unnecessary multicast traffic. IGMP helps ensure that multicast streams are only sent to the parts of the network that have active receivers, thus conserving bandwidth. This directly addresses the concern of excessive bandwidth usage mentioned in the question.
BSR can be used with the Hash fucntion to balance the load across multiple RPs.
I like this answer. Especially if the Video training is live and bidirectional, it would need to go through the (*,G) trees and all traffic pass through the RP. This would bog down the RP. If multiple training sessions are going on, maybe BSR would be hashin multiple RPs. But this is all conjecture. Cisco doesnt give us any details about whats really happening. Nevertheless, I would pick C: BSR
No good answer for this one. The question says "excessive" bandwidth usage is the concern. IGMP snooping will reduce the excessive bandwidth. It also says the RP has a high amount of bandwidth, which implies it can handle the video streaming application. But A says "IGMP" not "IGMP snooping", so this could be one of Cisco's stupid wording tricks to throw you off. I had this question on my exam, and it was worded exactly like this. I went with IGMP snooping, but I'm not 100% sure.
if a bandwidth usage is a concern , i will select A - IGMP
Yes, I agree. "IGMP snooping is a method that network switches use to identify multicast groups, which are groups of computers or devices that all receive the same network traffic. It enables switches to forward packets to the correct devices in their network."
Should be A
“C” seems to see correct. IGMP is used for end users to join multicast groups; it will not solve RP load or high BW usage.
If IGMP snooping is not in place, all multicast join requests are forwarded out of ALL vlans, ending up in a severe performance / bandwidth issue. By choosing option A, we have to assume IGMP was not there, even when it is a default on switches.
Answer: C Configure IGMP (Internet Group Management Protocol): Incorrect. IGMP is used by hosts to signal their interest in receiving multicast traffic. Deploy ICMP (Internet Control Message Protocol): Incorrect. ICMP is primarily used for diagnostic and error reporting purposes. Implement BSR (Bootstrap Router): Correct! BSR is a protocol that dynamically discovers and advertises the RP (Rendezvous Point) within a PIM-SM domain. By using BSR, the network can avoid the need for a static RP configuration. With BSR, the RP information is distributed automatically, reducing administrative overhead and allowing for more flexibility in RP selection. Implement STP (Spanning Tree Protocol): Incorrect. STP is used for loop prevention in Layer 2 networks.
If bandwidth is a concern, according to the Cisco Docs, IGMP should be the answer: IGMP provides a means to automatically control and limit the flow of multicast traffic throughout your network with the use of special multicast queries and hosts. BSR is better than static RP and has hash options (not enabled by default), but it is already a working network, even if it is with static RP.
A is the best answer as the BW is a concern, so we need to manage multicast traffic on the LANs as well.