HCIE-Datacom Changed H12-891_V1.0 Questions

Comprehensive and Detailed In-Depth Explanation:

TheOutbound Route Filtering (ORF)function in BGP allows a BGP speaker to inform its peer about the prefixes that it wants to receive, thereby reducing unnecessary route advertisements.

IP Prefix-List (D)is the correct answer because it is used to define the list of prefixes that are sent to the BGP peer during theORF capability negotiation.

Filter-policy (A)andRoute-policy (B)are used for controlling routing information locally or filtering incoming/outgoing routes but do not directly control the number of routes sent using ORF.

ACL (C)is primarily used for packet filtering and is not related to BGP route filtering.

Comprehensive and Detailed In-Depth Explanation:

In large- and medium-sized campus networks,Multi-mode authenticationis commonly used for PCs connected to IP phones. This is because multi-mode authentication allows:

Multiple authentication methods on the same interface,such as MAC address authentication for the IP phone and802.1X authentication for the PC.

This setup is ideal for scenarios where both devices share a single network port but require different authentication mechanisms.

MAC address authentication (A)and802.1X authentication (B)individually cannot accommodate both devices efficiently.

Portal authentication (D)is mainly used for guest access and is not practical for IP phone and PC connections.

ForSRv6 (Segment Routing over IPv6)deployment on abearer WAN, the following are essential:

IGP (OSPFv3 or IS-IS): Required for SID advertisement and SRv6 route computation →✅

BGP: Required when deployinginter-domain SRv6or for control plane distribution of VPN/service routes →✅

Not required:

MPLS: SRv6 replaces MPLS labels withIPv6-based SIDs→❌

BGP-LU: Used inMPLS-based inter-AS scenarios,not applicableto SRv6 →❌

Correct answers: B, C

Comprehensive and Detailed In-Depth Explanation:

NSR (Non-Stop Routing)andNSF (Non-Stop Forwarding)are high-availability mechanisms used to maintain network stability during routing process failures:

NSR (Non-Stop Routing):

Operates within thelocal router only.

Keeps routing information synchronized between theactive and standby processes.

Does not require collaboration from neighboring routers.

NSF (Non-Stop Forwarding):

Requires collaboration from neighboring routersthat support graceful restart.

The router undergoing failover relies on its neighbors tomaintain forwarding tableswhile control plane recovery takes place.

Neighboring routers must supportGR (Graceful Restart)for NSF to function correctly.

Therefore, the correct answer isBbecauseNSF requires neighboring router collaboration, whileNSR does not.