ICMPv6 messages are classified as error or informational messages.
ICMPv6 messages are classified into two types: error messages (e.g., Destination Unreachable, Time Exceeded) and informational messages (e.g., Echo Request, Echo Reply). This classification is fundamental to ICMPv6's operation .
When a routing policy is used to filter routes, which of the following route prefixes will be denied by the IP prefix below?
The prefix list permits the prefix 1.1.1.1/24 with a mask length greater than or equal to /26 and less than or equal to /32. This means only prefixes with the base 1.1.1.1 and mask lengths between /26 and /32 will be permitted. Routes like 1.1.1.2/16 and 1.1.1.1/24 do not meet the mask length criteria, so they will be denied. Conversely, routes like 1.1.1.1/26 and 1.1.1.1/32 satisfy the condition and will be permitted .
Which of the following statements regarding different LSA types is false?
LS Ack (Link State Acknowledgment) packets are used to acknowledge received LSAs and do not contain complete LSA information. Instead, they contain only the headers of LSAs being acknowledged. This contrasts with LS Update packets, which carry full LSA details. The misunderstanding of LS Ack functionality makes this statement false .
A router performs a lookup in its FIB table for a packet. If the tunnel ID in the matching entry is 0, the packet needs to be forwarded through a tunnel, such as an MPLS tunnel.
The question indicates that a router performs a lookup in its FIB table for a packet and determines that the tunnel ID in the matching entry is 0, suggesting that the packet needs to be forwarded through a tunnel such as an MPLS tunnel. However, this is a misunderstanding of the FIB functionality.
FIB Table Overview
The Forwarding Information Base (FIB) is used to make packet-forwarding decisions. Entries in the FIB include next-hop information, which can be directly linked to an interface or a tunnel.
If the Tunnel ID is 0, it indicates that the packet is forwarded via a normal routing path and not through a tunnel.
For MPLS or other tunnels, the Tunnel ID would have a non-zero value pointing to the associated tunnel.
MPLS Tunnel Operation
When a router forwards packets through an MPLS tunnel, a label-switched path (LSP) is set up. The FIB would reflect specific tunnel identifiers for packets that need such encapsulation.
HCIP-Datacom-Core Reference
Routing Principles and MPLSexplain the forwarding mechanisms clearly, stating that if a packet is routed normally, the tunnel ID remains 0.
The section on MPLSclarifies the encapsulation process and the role of tunnel identifiers.
Hence, the claim in the question is incorrect. A Tunnel ID of 0 implies no tunneling is required, and normal IP forwarding occurs
Which of the following statements regarding IGMPv1 and IGMPv2 are true?
IGMPv1 supports general queries but does not define a Leave message. IGMPv2 introduces the Leave message type, which allows hosts to notify routers when they wish to leave a multicast group, improving efficiency. These distinctions align with the functionality of IGMP versions .
