[UPDATED 2025] Free Huawei H12-831_V1.0 Exam Questions Self-Assess Preparation
H12-831_V1.0 Free Sample Questions to Practice One Year Update
NEW QUESTION # 40
Regarding the IPSG, which of the following statement is incorrect?
- A. IPSG can turn on the IP packet inspection and alarm function, and cooperate with the network management to perform alarms
- B. IPSG can prevent the host from changing the IP address privately
- C. IPSG is a source IP address filtering technology based on the three-layer interface
- D. IPSG can prevent IP address spoofing attacks
Answer: C
NEW QUESTION # 41
Service routes of an enterprise are transmitted on the network. Some configurations of PE1 and PE2 are shown in the figure. Which of the following LSAs may CE2 receive?
- A. Type 7 LSA
- B. Type 1 LSA
- C. Type 3 LSA
- D. Type 5 LSA
Answer: B,C
NEW QUESTION # 42
If you are faced with a complex network failure, and after evaluation, it is considered that the troubleshooting cannot be completed in a short time, and at this time the user urgently needs to restore the availability of the network, then which is the correct approach?
- A. Directly build an alternative network environment without notifying the customer
- B. Tell users that this is impossible
- C. Always try to troubleshoot, and do not inform users of the current difficulty of troubleshooting
- D. Communicate with users whether it is possible to skip the faulty node and build an alternative network environment
Answer: D
NEW QUESTION # 43
As shown in the figure, all interfaces of the router enable DSPF. The cost value of the link is marked in the figure. R2 The LoopbackD interface is advertised in area 1, then the cost of R1 reaching 10.2/32 is?
- A. 0
- B. 1
- C. 2
- D. 3
Answer: D
NEW QUESTION # 44
To ensure security, authentication can be configured in the OSPFV3 process area view.
- A. True
- B. False
Answer: A
NEW QUESTION # 45
Which of the following are the advantages of VLAN aggregation? (Multiple choice)
- A. Increased flexibility of addressing
- B. Reduce the waste of IP addresses
- C. Increased the number of available MLANs
- D. Realize the isolation of broadcast domains between Sub-VLANs
Answer: B,D
NEW QUESTION # 46
On the OSPFv3 network shown in the figure, OSPFv3 parameters use default values. The LSDB is checked on one of the devices. The router IDs of R1, R3, and R4 are 10.0.1.1, 10.0.3.3, and 10.0.4.4, respectively. The Origin Router part of some LSAs is hidden. Complete this part. (Tokens can be reused.)
Answer:
Explanation:
Explanation:
LSAs and Their Origin Router Associations:
* Link-LSA: Origin Router = 10.0.1.1
* Intra-Area-Prefix-LSA: Origin Router = 10.0.4.4
* Network-LSA: Origin Router = 10.0.3.3
* Inter-Area-Prefix-LSA: Origin Router = 10.0.1.1
NEW QUESTION # 47
During the process of viewing the debug output through the SSH terminal, a lot of information pops up. Which of the following operations can make the Moni tor terminal no longer pop up the debug message? (Multiple choice)
- A. Exit the current Moni tor interface, log in to the device again using SSH to open the new Monitor interface
- B. Open the notepad, enter undo debugging all, copy the command line, and paste it into the Monitor interface
- C. Open the notepad, enter undo terminal debugging, copy the command line, and paste it into the Monitor interface
- D. Open the notepad, enter undo terminal monitor, copy the command line, and paste it into the Monitor interface
Answer: C
NEW QUESTION # 48
On the network shown in the figure, EBGP peer relationships are established between ASs through directly connected interfaces.
* OSPF is deployed in AS 65456 (with OSPF disabled on interconnected interfaces between ASs).
* R4 and R5 use Loopback0 to establish iBGP peer relationships with R6.
* The IP address of Loopback0 on each router is 10.0.X.X/32, and the router ID is 10.0.X.X, where X is the number of the router.
* R1, R2, and R3 import the external route 192.168.1.0/24 into BGP through the import-route command.
Which of the following statements are true?
- A. For 192.168.1.0/24, R5 preferentially selects the route received from R2.
- B. For 192.168.1.0/24, if the default local-preference 150 command is configured on R3, R5 preferentially selects the route received from R3.
- C. For 192.168.1.0/24, R4 preferentially selects the route received from R1.
- D. For 192.168.1.0/24, R6 preferentially selects the route received from R4.
Answer: A,B
Explanation:
Comprehensive and Detailed In-Depth Explanation:
Understanding the BGP and OSPF Network Topology in the Question:
* External Route Importation
* R1, R2, and R3 import 192.168.1.0/24 into BGP from an external source.
* This means R1, R2, and R3 will advertise this route to their EBGP and iBGP peers.
* BGP Route Selection Criteria
* BGP follows specific rules to determine the best path for a route. The most relevant factors here are:
* Highest Local Preference (LOCAL_PREF) # Preferred
* Shortest AS Path # Preferred
* Lowest Origin Type (IGP < EGP < Incomplete) # Preferred
* Lowest MED (Multi-Exit Discriminator) # Preferred
* Oldest eBGP route (if paths are equal) # Preferred
Route Selection Analysis for Each Statement:
A: For 192.168.1.0/24, R5 preferentially selects the route received from R2. # (Correct)
* R5 is in AS 65456 and peers with R6 using iBGP.
* Since R2 is a central router with direct connectivity to R5, it is the most preferred path compared to indirect paths from R1 or R3.
* By default, R5 will prefer the path from R2 over others unless explicitly influenced by BGP attributes.
# Statement A is correct.
B: For 192.168.1.0/24, R4 preferentially selects the route received from R1. # (Incorrect)
* R4 and R5 use Loopback0 to establish iBGP with R6, meaning they receive BGP routes from multiple sources.
* BGP prefers the shortest AS path, and there is no specific information indicating that R1's path is the shortest for R4.
* R4 may actually prefer another router's advertisement (e.g., R2 or R3) depending on AS path length and other attributes.
# Statement B is incorrect.
C: For 192.168.1.0/24, if the default local-preference 150 command is configured on R3, R5 preferentially selects the route received from R3. # (Correct)
* By default, BGP assigns a local-preference of 100.
* If R3 sets local-preference to 150, it is higher than other routes (R1, R2).
* BGP prefers the highest local-preference value, so R5 will prefer the route received from R3 if this attribute is set.
# Statement C is correct.
D: For 192.168.1.0/24, R6 preferentially selects the route received from R4. # (Incorrect)
* R6 is an iBGP peer of both R4 and R5.
* BGP best-path selection depends on attributes like local-preference, AS-path, and MED.
* There is no explicit information suggesting that R4's advertisement is preferred over R5's.
* R6 may prefer R5's route depending on attributes.
# Statement D is incorrect.
Final Conclusion:
# A. R5 preferentially selects the route received from R2.# B. R4 does not necessarily prefer R1's route.
# C. If R3 sets local-preference 150, R5 will prefer the route from R3.# D. R6 does not necessarily prefer R4's route.
Thus, the correct answers are: A, C.
NEW QUESTION # 49
The figure shows information about VPN1 on a PE (Provider Edge) router in a BGP/MPLS IP VPN network.
When the VPNv4 route corresponding to VPN1 is advertised to the remote PE, which VPNs of the remote PE will accept the route?
VPN1 Configuration:
ip vpn-instance VPN1
ipv4-family
route-distinguisher 100:1
vpn-target 100:1 200:1 300:1 export-extcommunity
VPN Import Policies on the Remote PE:
- A. VPN4: Import RT=500:1
- B. VPN2: Import RT=200:1, 400:1
- C. VPN3: Import RT=100:1, 300:1
- D. VPN1: Import RT=100:1
Answer: D
Explanation:
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).
NEW QUESTION # 50
On the network shown in the figure, EBGP peer relationships are established between neighboring routers through directly connected interfaces.
* The router ID of each router is 10.0.X.X, and the AS number is 6500X, where X is the number of the router.
* Both R1 and R4 have static routes to 192.168.1.0/24, which are imported to BGP through the import-route command.
* R1 adds a community attribute (1:1) to the route before advertising it to its peers.
* All routers are configured to propagate community attributes.
* R3 is configured with a routing policy that rejects routes with the community attribute 1:1.
In this case, which of the following is the path for traffic from R3 to 192.168.1.0/24?
- A. R3 does not have a route to 192.168.1.0/24
- B. R3 # R2 # R4
- C. R3 # R5 # R1
- D. R3 # R2 # R1
Answer: C
Explanation:
Comprehensive and Detailed In-Depth Explanation:
Understanding the BGP Network Topology in the Question:
* BGP Peering & Route Distribution
* Each router forms EBGP peer relationships with directly connected neighbors.
* R1 and R4 import the static route 192.168.1.0/24 into BGP and advertise it to their peers.
* Community attributes are attached to routes to influence routing policies.
* Effect of Community Attribute 1:1
* R1 marks 192.168.1.0/24 with community 1:1 before advertising it.
* R3 has a policy that rejects any routes with community attribute 1:1.
* Since R1's advertisement contains 1:1, R3 will not accept 192.168.1.0/24 from R2.
Route Selection and Traffic Flow Analysis:
* R1 advertises 192.168.1.0/24 with community 1:1 to R2.
* R3 rejects this route from R2 because of the configured routing policy.
* R4 also advertises 192.168.1.0/24 to its EBGP neighbors without community 1:1.
* R5 learns the route from R4 and advertises it to R3.
* Since R5's advertisement does not include community 1:1, R3 accepts the route from R5.
* Thus, the best available path for R3 to reach 192.168.1.0/24 is R3 # R5 # R1.
# Correct Path: R3 # R5 # R1
Checking Each Option:
# Option A: R3 # R2 # R4 (Incorrect)
* R3 does not learn the route from R2 because it rejects community 1:1.
* Since R1 added 1:1, and R2 propagated the same community, R3 will not accept this path.
# Option B: R3 does not have a route to 192.168.1.0/24 (Incorrect)
* R3 does have a route, but it learns it from R5 instead of R2.
# Option C: R3 # R2 # R1 (Incorrect)
* R1 marked the route with 1:1, and R2 advertised it with the same community.
* Since R3 rejects 1:1 routes, it will not use this path.
# Option D: R3 # R5 # R1 (Correct)
* R5 learns the route from R4, which does not have community 1:1, and advertises it to R3.
* R3 accepts this route and forwards traffic to R5, which sends it to R1.
Final Conclusion:
# D. The correct path for traffic from R3 to 192.168.1.0/24 is R3 # R5 # R1.
Thus, the correct answer is: D.
NEW QUESTION # 51
(Connection question) Please correspond the alarm level with the importance of the fault and the countermeasures. (Multiple choice)
Answer:
Explanation:
NEW QUESTION # 52
An engineer uses two routers to test IPv6 services, and simulates the headquarters and branches by running BGP4+ of interconnection. As shown in the figure, an engineer captures packets to view the update packets sent by R1. About this message Description of information, which of the following statements is correct
- A. The next hop address of the route described in this packet is:2001:db8::2345:l.:l
- B. This message describes the current revocationIPv6routing
- C. the route described in this packet may be throughimportbow
Answer: C
NEW QUESTION # 53
On the OSPF network shown in the figure, a network engineer finds that R1 and R2 have the same router ID, and both have imported default routes (with the default-route-advertise always command configured). Given this, which of the following statements is false?
- A. A routing loop may occur between R3 and R4.
- B. R1 and R3 can establish a neighbor relationship.
- C. R1 and R2 can establish a neighbor relationship.
- D. R2 and R4 can establish a neighbor relationship.
Answer: C
NEW QUESTION # 54
Which of the following functions will affect the establishment of BGP neighbors? (Multiple choice)
- A. ebgp max hop
- B. BGP GSTM
- C. BGP route filtering
- D. BGP authentication
Answer: A,B,D
NEW QUESTION # 55
A park deployed IPv6 for business testing. There are 4 routers in the network, running OSPFV3 to realize the interconnection and intercommunication of IPv6 networks. As shown in the figure, an engineer checked the LSDB of R2 and intercepted one of the Link-LSAs. Regarding the description of the LSA, which of the following statements are correct? (Multiple choice)
- A. The LSA shows that R2 does not support external routing, but participates in IPv6 routing calculations
- B. The IPv6 address prefix of the R2 interface GE0/0/0 is 2001:2343: 23: :/64
- C. The router that generated the LSA is R2
- D. The link-local address of the R2 interface GE0/0/0 is FE80::2E0; FCFF:FECD:4F79
Answer: B,C,D
NEW QUESTION # 56
Deploying port isolation technology in Ethernet can realize Layer 2 intercommunication and Layer 3 isolation, making networking more flexible.
- A. correct
- B. mistake
Answer: B
NEW QUESTION # 57
On the OSPF network shown in the figure, the cost values of links are marked, and OSPF IP FRR is enabled on R1. Which of the following statements is false?
- A. If the link between R2 and SI is disconnected, R1 recalculates the optimal path to R3 and performs path switching instantly.
- B. If the link between R1 and SI is disconnected, R1 directly uses the backup path to forward packets to R3 because FRR is enabled on R1.
- C. If the link between R1 and SI is disconnected, Rl recalculates the optimal path to R3 and performs path switching instantly.
- D. If the link between R1 and SI is disconnected and you check neighbor information on R1, the neighbor relationship between R1 and R2 will instantly display Down.
Answer: C
NEW QUESTION # 58
On the network shown in the figure, the network administrator configures the DHCP snooping trust function on the switch.
* GE0/0/2 is a trusted interface (connected to the DHCP Server).
* GE0/0/3 is an untrusted interface (potential attacker).
Which of the following statements are true about the two interfaces?
Options:
- A. When receiving a DHCP response packet on GE0/0/2, the switch forwards the packet through GE0/0/1.
- B. When receiving a DHCP response packet on GE0/0/3, the switch forwards the packet through GE0/0/1.
- C. When receiving a DHCP request packet on GE0/0/3, the switch forwards the packet through GE0
/0/2. - D. When receiving a DHCP request packet on GE0/0/2, the switch forwards the packet through GE0
/0/3.
Answer: A,C
Explanation:
Comprehensive and Detailed In-Depth Explanation:
1. Understanding DHCP Snooping
DHCP Snooping is a security feature that filters untrusted DHCP messages to prevent attacks such as:
* Rogue DHCP servers distributing incorrect IP addresses.
* DHCP starvation attacks.
In DHCP Snooping, switch ports are classified as:
* Trusted Interfaces: Allow both DHCP requests and DHCP responses to pass through.
* Untrusted Interfaces: Allow only DHCP requests but drop DHCP responses (to prevent rogue DHCP servers).
2. Analyzing Each Answer Option
* Option A: "When receiving a DHCP response packet on GE0/0/2, the switch forwards the packet through GE0/0/1."
* Correct.
* GE0/0/2 is a trusted interface (connected to the DHCP server).
* DHCP responses (ACK, NAK, OFFER) come from the DHCP Server.
* Since DHCP responses are allowed on trusted interfaces, the switch forwards them to the client (PC1) via GE0/0/1.
* Option B: "When receiving a DHCP request packet on GE0/0/2, the switch forwards the packet through GE0/0/3."
* Incorrect.
* DHCP requests originate from clients (PC1, attackers, etc.), not from the DHCP server.
* The DHCP request should be forwarded to the DHCP server via a trusted interface (not GE0/0
/3, which is untrusted).
* Option C: "When receiving a DHCP response packet on GE0/0/3, the switch forwards the packet through GE0/0/1."
* Incorrect.
* GE0/0/3 is an untrusted interface (connected to the attacker).
* DHCP responses (ACK, OFFER) from untrusted interfaces are dropped to prevent rogue DHCP attacks.
* The switch will not forward the packet.
* Option D: "When receiving a DHCP request packet on GE0/0/3, the switch forwards the packet through GE0/0/2."
* Correct.
* DHCP requests originate from clients (PC1 or attacker).
* Since DHCP requests are allowed on untrusted interfaces, the switch forwards them to the DHCP server via the trusted interface (GE0/0/2).
Final Answer:
# A and D are correct.
HCIP-Datacom-Advanced Routing & Switching Technology References:
* DHCP Snooping and Port Trust Classification
* How Trusted and Untrusted Ports Handle DHCP Packets
* Preventing Rogue DHCP Servers Using DHCP Snooping
NEW QUESTION # 59
In an intra-domain MPLS VPN network, when a data packet enters the public network and is forwarded, it will be encapsulated with two layers of MPLS labels. Which of the following description is wrong about the two layers of labels? (Multiple choice)
- A. The outer label is used to correctly send the data packet to the corresponding VPN on the PE device
- B. The outer label of MPLS VPN is allocated by the LDP protocol or statically, and the inner label is allocated by the MP-BGP neighbor at the correct end.
- C. By default, the outer label is ejected before the packet is forwarded to the last-hop device
- D. The outer label of MPLS VPN is called the private network label. The inner label is called the public network label.
Answer: A,D
NEW QUESTION # 60
An engineer uses two routers to test IPv6 services, and simulates the headquarters and branches by running BGP4+ of interconnection. As shown in the figure, an engineer captures packets to view the update packets sent by R1. About this message Description of information, which of the following statements is correct
- A. The next hop address of the route described in this packet is:2001:db8::2345:l.:l
- B. This message describes the current revocationIPv6routing
- C. the route described in this packet may be throughimportbow
Answer: C
NEW QUESTION # 61
Link LSAs of OSPFv3 are propagated throughout the area.
- A. right
- B. wrong
Answer: B
NEW QUESTION # 62
Which of the following description of the configuration on this switch is correct? (Multiple choice)
- A. The VANIF100 interface will send the received DHCP messages to the external DHCP Server through the relay
- B. Specify the DHCP server group as dhcpgroup1 for the VLAN100 interface
- C. To configure the DHCP server and DHCP relay, DHCP must be enabled globally
- D. First, you need to create a DHCP server group and add a DHCP server to the server group
Answer: A,B,C,D
NEW QUESTION # 63
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