H12-831_V1.0 Exam Dumps : HCIP-Datacom-Advanced Routing & Switching Technology V1.0

In OSPFv3, several new LSA types were introduced to support IPv6. The Link-LSA and Intra-Area-Prefix-LSA have the following roles:

✅ Link-LSA is generated per link by each router. It includes:

Link-local IPv6 address

IPv6 prefix(es) associated with the link

Options related to the interface (bitfields)

✅ Intra-Area-Prefix-LSA describes IPv6 prefix information associated with a Router-LSA or a Network-LSA, rather than embedding it directly within them (as in OSPFv2).

❌ A device does not generate an Intra-Area-Prefix-LSA for each link; instead, it generates it per area, and it can contain multiple prefixes.

✅ Official Reference from Huawei:

" In OSPFv3, prefix information is no longer carried in Router-LSAs or Network-LSAs. Instead, Intra-Area-Prefix-LSAs are used to describe prefixes associated with them. "

" Each router generates one Link-LSA per link. The Link-LSA includes the link-local address and the list of IPv6 prefixes for the link. "

— [Huawei HCIA-Datacom Certification Guide – OSPFv3 Chapter]

Comprehensive and Detailed In-Depth Explanation:

1. Understanding Route Targets (RT) and Route Distribution in MPLS VPN

MPLS Layer 3 VPNs (L3VPNs) use BGP to distribute VPN routes across multiple Provider Edge (PE) routers.

Each VPN instance (VRF) is configured with Route Targets (RTs) to control which VPN routes are imported/exported.

Route Distinguishers (RDs) are unique per VRF but do not affect route selection.

2. Analyzing VPN1 Configuration

VPN1 is exporting routes with the following Route Targets (vpn-target values):

100:1

200:1

300:1

Remote VPNs will import these routes only if their import RT list matches one of the exported RTs.

3. Matching Exported RTs with Import RTs in Remote VPNs

Remote VPN

Import RTs

Matches VPN1 Exported RTs (100:1, 200:1, 300:1)?

Accepts the Route?

VPN1

100:1

✅ Matches 100:1

✅ Yes

VPN2

200:1, 400:1

✅ Matches 200:1

✅ Yes

VPN3

100:1, 300:1

✅ Matches 100:1, 300:1

✅ Yes

VPN4

500:1

❌ No match

❌ No

✅ VPN1, VPN2, and VPN3 accept the route.

❌ VPN4 does not accept the route because 500:1 is not in the export list of VPN1.

Final Conclusion:

✅ Correct Answer: VPN1, VPN2, and VPN3 will accept the route.

❌ VPN4 does not accept the route because there is no matching RT.

Thus, the correct answer is:

✅ A. VPN1: Import RT=100:1

✅ B. VPN2: Import RT=200:1, 400:1

✅ C. VPN3: Import RT=100:1, 300:1

❌ D. VPN4: Import RT=500:1 (No match, does not accept the route).

OSPFv3 introduces Link-LSAs to advertise link-local addresses, IPv6 prefixes, and relevant interface options to routers connected to the same link.

Unlike Router-LSAs and Network-LSAs, a Link-LSA provides IPv6 addressing information associated with a particular interface.

In the displayed Link-LSA, the field Number of Prefixes has a value of 3. Three IPv6 prefix entries are listed: 2000:14::/64, 2001:14::/64, and 2002:14::/64.

The exhibit also includes a link-local IPv6 address beginning with FE80::. This address belongs to the link-local address space and must not be counted as a global unicast prefix.

Therefore, the intended examination interpretation is that the interface has three global unicast address prefixes.

Strictly, an LSA ' s prefix count does not independently prove the precise number of individual interface addresses, but among the provided options, D is the intended answer.