Since the attribute AS-PATH cannot work well in the AS, it is stipulated that BGP routers will not announce any update information from IBGP peers to its IBGP peers.
- A . True
- B . False
Inject the BGP route by redistributing the command, and its ORIGIN attribute is INCOMPLETE.
- A . True
- B . False
AS (AUTONOMOUS SYSTEM) refers to a group of routers that are defined independently by users and use a unified routing strategy.
- A . True
- B . False
The master-slave relationship of OSPF neighbors is negotiated through DD packets.
- A . True
- B . False
IGMPv1 only contains two message types: membership query and membership report.
- A . True
- B . False
When two routers establish a logical BGP peer through multiple physical links, the peer connect-interface command must be used.
- A . True
- B . False
For link state routing protocols, filtering routes in the inbound direction can actually block the transmission of link state information. The effect of filtering is that the route cannot be added to the local routing table, and its neighbors cannot receive the complete Route status information.
- A . True
- B . False
In the OSPF routing protocol, the LSA types involved in the calculation of intra-area routes are only Router-LSA, Network-LSA and Summary LSA.
- A . True
- B . False
When two routers exchange database information through DD messages, a master-slave relationship is first formed, the one with the larger ROUTER ID must be the master, and the slave bit is determined to be MS.
- A . True
- B . False
LS Sequence Number is used to detect expired and repeated LSA. It is a 32-bit signed integer, so the largest LS SEQUENCE NUMBER is 0X7FFFFFFF.
- A . True
- B . False
In the same LAN, if some IGMP V1 routers exist in the LAN, then IGMP V1 must be configured for all routers in the subnet for normal use.
- A . True
- B . False
The access control list (acl) is the order of matching rules, which can be matched regardless of the order in which the user configures the ACL rules.
- A . True
- B . False
On non-broadcast networks, OSPF has two modes of operation, non-broadcast multiple access and point-to-multipoint. Non-broadcast multiple access requires DR/BDR election.
- A . True
- B . False
By default in the VRP version, when the route-policy of a BGP neighbor is changed, it will automatically send a REFRESH to the neighbor to request the neighbor to resend the UPDATE message.
- A . True
- B . False
In the BGP routing rules, the route with the higher MED value is preferred.
- A . True
- B . False
Multiple BGP processes cannot be configured on a router.
- A . True
- B . False
In the MSTP protocol, each MST INSTANCE uses the RSTP algorithm separately to calculate a separate spanning tree.
- A . True
- B . False
The OSPF NBMA network type requires that the routers in the network must select DR and BDR, or they cannot work.
- A . True
- B . False
IS-IS routers with an interface priority of 0 cannot participate in the DIS election.
- A . True
- B . False
The IP-Prefix can be used for routing information filtering.
- A . True
- B . False
The ABR in the OSPF complete STUB area does not flood the third, fourth, and fifth type LSAs into the area. Therefore, the ABR in the complete STUB area needs to manually delegate a default route to the area to guide how data packets reach the outside destination of the AS.
- A . True
- B . False
IGMP Snooping runs at the data link layer, used to manage, and control multicast groups, and solve the problem of multicast packets broadcast at the third layer.
- A . True
- B . False
When the BGP versions supported by two BGP neighbors are inconsistent, the neighbors will negotiate to use the highest BGP version that both ends can support.
- A . True
- B . False
Every DD message has a DD sequence number, which is used for the confirmation mechanism of the DD message. DD contains complete link status information.
- A . True
- B . False
By default, the OSPF port cost is related to the port bandwidth. The calculation formula is: BANDWIDTH-REFERENCE/BANDWIDTH. The port cost can only be calculated by OSPF and cannot be changed manually.
- A . True
- B . False
Port isolation can isolate the communication between different ports in the same VALN of the same switch.
- A . True
- B . False
OSPF supports multi-process, multiple different OSPF processes can run on the same router, they do not affect each other and are independent of each other. The routing interaction between different OSPF processes is equivalent to the routing interaction between different routing protocols.
- A . True
- B . False
The import-route limit command cannot limit the maximum number of external routes that can be imported in an OSPF process.
- A . True
- B . False
By default in VRP, when the route-policy of a BGP neighbor is changed, manual operations are required to re-send the UPDATE information to the neighbor.
- A . True
- B . False
In OSPF, the DR and BDR elected in the broadcast type network listen to both the 240.0.0.5 address and the 24.0.0.6 address.
- A . True
- B . False
The function of routing protocol priority is to assign different priorities to the routes discovered by different protocols, so that when a router learns the same route from different routing protocols at the same time, it can have a priority order of selection.
- A . True
- B . False
By default, VRP automatically aggregates routes imported by BGP.
- A . True
- B . False
OSPF divides the boundary of the area on the router.
- A . True
- B . False
The ABR in the OSPF STUB area does not flood Type 5 LSA, Type 4 LSA, and Type 3 LSA into the STUB area. Therefore, the STUB area does not have AS external routing capabilities. The ABR in the STUB area advertises a default route to the area, guiding to send to destination outside the AS.
- A . True
- B . False
OSPF runs directly on top of the TCP protocol, using TCP port number 179.
- A . True
- B . False
If the Router Priority is set to 0, then in the OSPF routing domain, the router is allowed to be elected as DR or BDR, but with the lowest priority.
- A . True
- B . False
There can be multiple nodes under one ROUTE-POLICY, different node numbers are identified by sec-number, and the relationship between the various parts of different seq-numbers is an "or" relationship.
- A . True
- B . False
Different network types of the OSPF protocol can form an adjacency in the FULL state.
- A . True
- B . False
Using default routing between routers is a low-cost solution, but requires more system resources than a complete routing table.
- A . True
- B . False
The AS border router can be an internal router IR or ABR, and must belong to the backbone area.
- A . True
- B . False
The default value of the OSPF DR-PRIORITY command is 1, and the value range is 0-255.
- A . True
- B . False
BGP neighbors establish neighbor relationships through UDP.
- A . True
- B . False
In order to avoid inter-area loops, OSPF stipulates that it is not allowed to advertise routing information directly between two non-backbone areas. It is only allowed to advertise routing information within an area or between a backbone area and a non-backbone area. Therefore, each area border router (ABR) must be connected to the backbone area.
- A . True
- B . False
Unicast technology and multicast technology have different advantages in solving the problem of single-point sending and multi-point receiving.
- A . True
- B . False
Every router running OSPF has a ROUTER ID, which must be published in OSPF.
- A . True
- B . False
In the OSPF routing domain, a broadcast network and an NBMA network containing at least two routers must designate one router as DR and the other as BDR.
- A . True
- B . False
On the VRP platform, when we introduce OSPF or ISIS routing to RIP, if the COST is not specified, the cost value will be set to 16.
- A . True
- B . False
By default, in order to successfully transfer routing information to IBGP peers, the BGP Speaker must establish IBGP connections with other BGP peers to form an IBGP full interconnection within the AS.
- A . True
- B . False
When the Hold Time parameter negotiated by two BGP neighbors is 0, the Keeplive message is not sent.
- A . True
- B . False
In the ospf routing protocol, the unit of the bandwidth-reference command is mbps.
- A . True
- B . False
In OSPF broadcast or NBMA network types, devices with a large ROUTER PRIORITY may not necessarily become DR.
- A . True
- B . False
On the broadcast or nbma network, not all neighbors will establish adjacency.
- A . True
- B . False
The OSPF vlink-peer command is used to configure a virtual connection, which specifies the router-id of the peer.
- A . True
- B . False
The matching order of the access control list is divided into two types: configuration order and automatic sorting.
- A . TRUE
- B . False
When the Hold Time supported by two BGP neighbors are inconsistent, the neighbors will negotiate to adopt the lowest Hold Time interval that both ends can support.
- A . True
- B . False
In the OSPF routing protocol, under the same other conditions, the Type 2 of external route always takes precedence over the Type 1 of external route.
- A . True
- B . False
In the OSPF protocol, it is not possible to judge the newness of the same LSA based on LS SEQUENCE NUMBER and LS AGE alone.
- A . True
- B . False
When different routing protocols are used in unused networks, and these networks need to share routing information, you can set up route import. In BGP, routes can only be imported through the network.
- A . True
- B . False
In the BGP routing rules, the route with the higher LOCAL_PREF value takes precedence.
- A . True
- B . False
In the routing rules of BGP, the priority of the manually aggregated route generated by the AGGREGATE command is higher than the automatically aggregated route generated by the SUMMARY AUTOMATIC command.
- A . True
- B . False
Two level-1 routers in different areas can form a neighbor relationship.
- A . True
- B . False
The active tree uses the shortest path from the multicast source to the receiver, so it is called the shortest path tree SPTA.
- A . True
- B . False
The first 4BIT of the IP multicast address is a fixed 1110, corresponding to the high 25BIT of the multicast MAC address. Only 23BIT of the last 28BIT of the IP multicast address is mapped to the MAC address, so the address information of 5BIT is lost. The direct result is that there are 32 IP multicast addresses mapped to the same MAC address.
- A . True
- B . False
In a network running STP, a variety of topology change information will be sent when the network topology changes. How many types of topology change information are defined in the RSTP network?
- A . One
- B . Two
- C . Three
- D . Four
The state where no connection is established between BGP neighbors and no attempt is made to establish a connection is:
- A . Established
- B . Idle
- C . Active
- D . Openconfirm
In the RSTP protocol, the uplink port of a non-root switch has a port identification parameter. This port identification consists of two parts, namely:
- A . One-byte port priority and one-byte port number
- B . One-byte port priority and two-byte port number.
- C . Two-byte port priority and one-byte port number
- D . Two-byte port priority and two-byte port number
Which of the following is a feature of OSPF stub area?
- A . AS-external-LSA is allowed to be published in the STUB area.
- B . The route to the outside of the AS can only be based on a default route manually generated by ABR.
- C . Virtual connection cannot cross STUB AREA
- D . Any area can become a STUB area
Which of the following description is wrong about the OSPF protocol?
- A . When a router receives a NETWORK-Summary-LSA, the router runs the SPF algorithm
- B . NETWORK-LSA is used to describe the link state information of the broadcast network segment and the NBMA network segment.
- C . A virtual link is a virtual link belonging to the backbone area AREA 0).
- D . The Type 4 of LSA is used to describe how to reach the ASBR and contains routing and topology information.
As shown in the figure below, if you want employees of department A to not communicate with each other, employees of department B can communicate with each other, but different departments cannot communicate with each other, and all employees can access the company’s server through MUX VLAN. To achieve this function, which of the following statement is correct?
- A . VLAN 2 is set to interoperable VLAN
- B . VLAN 100 is the slave VLAN
- C . VLAN 3 is set as the main VLAN
- D . VLAN 3 is set to interoperable VLAN
When a router running OSPF receives an LSA, and the LSA does not exist in its link state database, how will the router handle this LSA?
- A . The router will silently discard this LSA without returning any messages.
- B . This LSA will be flooded to other OSPF neighbors immediately.
- C . The LSA will be installed in its own link state database, and then the LSA will be confirmed through multicast.
- D . Check the Age of the LSA to see if it has expired.
Regarding the distribution tree, which of the following description is correct? (Multiple Choice)
- A . The multicast distribution tree with the multicast source as the root and the multicast group members as the leaves is called RPT.
- B . The multicast distribution tree with RP (RENDEZVOUS POINT) as the root and multicast group members as leaves is called SPT.
- C . SPT is applicable to both PIM-DM and PIM-SM
- D . RPT is applicable to both PIM-DM and PIM-SM
Regarding the LSA of all kinds of message, which of the following description is wrong?
- A . DD type LSA only contains the summary information of LSA, that is, it contains LS TYPE, LSID, ADVERTISING ROUTER and LS SEQUENCE NUMBER
- B . LS REQUEST message only has LS TYPE, LS ID and ADVERTISING ROUTER
- C . LS UPDATE packet contains complete LSA information
- D . LS ACK packet contains complete LSA information
Which of the following reasons can cause the BGP neighbor relationship to fail to be established?
- A . An ACL that blocks all TCP connections is configured between the two BGP neighbor relationships
- B . IBGP neighbors are not directly connected physically.
- C . bgp synchronization is enabled in the fully interconnected IBGP neighbor relationship
- D . The update time between the two BGP neighbors is inconsistent.
When using manual link aggregation mode, which of the following description regarding adding member interfaces is wrong?
- A . Eth-Trunk interfaces cannot be nested, that is, member interfaces cannot be Eth-Trunk.
- B . An Ethernet interface can only be added to any th-Trunk interface. If you need to add another Eth-Trunk interface, you must first exit the original Eth-Trunk interface.
- C . If the local device uses Eth-Trunk, the peer interface directly connected to the member interface must also be bundled as an Eth-Trunk interface so that both ends can communicate normally.
- D . Eth-Trunk has two working modes: Layer 2 working mode and Layer 3 working mode. Two working modes are automatically recognized, no need to switch manually.
Regarding the static LACP mode, which of the following statement is wrong?
- A . When you need to provide a larger link bandwidth between two directly connected devices and the opposite device does not support the LACP protocol, you can choose to use the manual load sharing mode.
- B . In static LACP mode, the greater the LACP priority value of the interface, the higher the priority, the easier it is to select the active port.
- C . In the static LACP mode, the interface that forwards data is called the active interface, and the interface that does not forward data is called the inactive interface. Only when the active interface fails, the backup interface can be changed from an inactive interface to an active interface.
- D . If preemption is enabled, the backup interface with high quality and failure level will become the active interface after a certain time delay after the active interface fails; if preemption is enabled, the failed interface cannot automatically become the active interface.
MUX VLAN provides a mechanism for network resource control through VLAN. Which of the following concepts do not belong to MUX VLAN?
- A . Primary VLAN
- B . Slave VLAN
- C . Guest VLAN
- D . Interworking VLAN
In the process of BGP establishing a neighbor, when TCP cannot be successfully established, what is the status of the neighbor?
- A . Idle
- B . Active
- C . OpenSent
- D . Establish
MSTP solves many shortcomings of the single spanning tree of RSTP and STP. Regarding the MSTP, which of the following description is correct?
- A . Each MST INSTANCE uses a separate STP algorithm to calculate a separate spanning tree
- B . Each MST INSTANCE has an identifier, MSTID is a one-byte integer
- C . All VLANs are mapped to MST INSTANCE 1 by default
- D . MSTP allows one or more VLANs to be mapped to a MST instance, MSTP calculates the root switch separately for each MST INSTANCE, and sets the port status separately
When a router running BGP receives a route with an unreachable next hop, how to deal with it?
- A . Send an error message to the router that issued the Update.
- B . Refuse to join the BGP routing table, and silently discard it.
- C . Receive the route and add it to the BGP routing table. But this route will not be preferred by BGP and will not be added to the IP routing table.
- D . Receive the route, add it to the BGP routing table, and participate in the BGP routing rules. It may be selected as the best route and add it to the IP routing table.
In the broadcast network, what mechanism does the IS-IS protocol use to ensure the reliability of neighbor relationship establishment?
- A . State synchronization
- B . Checksum
- C . Aging timer
- D . Three handshake
In a broadcast type network, what is the default time interval for DIS to send HELLO?
- A . 5S
- B . 10s
- C . 3.3S
- D . 40S
Which of the following types of LSA can carry TAG information for external routes?
- A . LSA5
- B . LSA4
- C . LSA3
- D . LSA2
With regard to the Stub area, the correct understanding of the Stub area and NSSA is:
- A . The STUB area can only flood the Type 3 LSA, and the complete STUB area cannot flood any Type 3 LSA.
- B . The biggest difference between a fully stub area and a stub area is that Type 3 LSAs cannot be flooded
- C . The STUB area can import AS external routes, but NSSA cannot import AS external routes
- D . The STUB area can flood Type 3 and Type 4 LSAs, and the complete STUB area cannot flood Type 3 and Type 4 LSAs
Which of the following descriptions about MUX VLAN is wrong?
- A . Each GROUP VLAN must be bound to a RINCIPAL VLAN
- B . If the VLAN ID has been used for the PRINCIPAL VLAN, then the VLAN can no longer be used for the VLANIF interface, SUPER VLAN, and SUB VLAN
- C . After the port is enabled with the MUX VLAN function, it can also be used for VLAN MAPPING and VLAN STACKING configuration
- D . Enterprises can use PRINCIPAL PORT to connect to the corporate server, SEPARATE PORT to connect to corporate customers, and GROUP PORT to connect to corporate employees, so that can achieve the purpose of corporate customers and employees accessing the corporate server, while corporate employees can communicate with each other, but not between corporate customers, the corporate customers and corporate employees cannot access to each other.
Regarding the description of OSPF route aggregation, which of the following is wrong?
- A . Route aggregation refers to the aggregation of routing information of the same prefix, and only advertises one route to other areas
- B . Through route aggregation, routing information can be reduced, thereby reducing the size of the routing table, and improving the performance of the router
- C . OSPF has two route aggregation methods, ABR aggregation and ASBR aggregation
- D . Any router in OSPF can perform route aggregation operations
The following is a partial configuration of a router. Which part of the configuration description is correct?
ip IP- prefix pl permit 10.0. 192.0 8 greater-equal 17 less-equal 18
- A . In the 10.0.192.0/8 network segment, the route with a mask length of 18 will be matched to the prefix list, and the matching rule is allowed.
- B . In the 10.0.192.0/8 network segment, the route with a mask length of 19 will be matched to the prefix list, and the matching rule is allowed.
- C . In the 10.0.192.0/8 network segment, the route with a mask length of 20 will be matched to the prefix list, and the matching rule is allowed.
- D . In the 10.0.192.0/8 network segment, the route with a mask length of 21 will be matched to the prefix list, and the matching rule is allowed.
The following is about the ROUTER-LSA connection type (Type), which of the following description is wrong?
- A . POINT-TO-POINT describes a point-to-point connection from this router to neighboring routers
- B . TRANSNET describes the connection from this router to a TRANSIT network segment
- C . STUBNET describes a connection from this router to a STUB network segment
- D . P2MP describes the connection of a local router to multiple neighbor routers
Although the STP protocol can solve the loop problem, the slow convergence of the network topology affects the quality of user communication. RSTP has made many improvements to STP. Which of the following is not an improvement of RSTP to STP?
- A . RSTP’s port state specification is divided according to whether the port forwards user traffic and learns MAC addresses, reducing the original 5 port states to 3
- B . The non-root switch running RSTP sends configuration BPDUs at the interval specified by the Hello Timer. This behavior is completely performed by each device independently
- C . RSTP deletes 3 port states and adds 2 new port roles
- D . If a port does not receive the configuration BPDU sent by the upstream device within 4 consecutive Hello Time, the device considers that the negotiation with the neighbor has failed
About information description of ASBR-Summary-LSA of OSPF, which of the following statement is wrong?
- A . Link State indicates the Router ID of ASBR
- B . Advertising Router represents the Router ID of the ABR
- C . The Advertising Router field in the ASBR-Summary-LSA of all areas is the same.
- D . Metric represents the OSPF cost of the ABR to the ASBR
Regarding the description of OSPF external routing types, which is wrong?
- A . OSPF is divided into the Type 1 of external routing and the Type 2 of external routing.
- B . The cost value of OSPF type 1 external route is only the external cost value of the AS, and the internal cost value of the interconnected AS
- C . The cost of OSPF type 2 external routes is the sum of the internal cost of the AS and the external cost of the AS
- D . Under the same conditions, OSPF’s type 1 of external route always takes precedence over the Typle 2 of external route
The following is part of the information output by the router Huawei. Which of the following description of this part of information is wrong?
- A . The display pim rp-info command is used to view the RP information corresponding to the multicast group
- B . The RP address is 2.2.2.2.
- C . The priority of RP is 0
- D . The group address is 225.0.0.0
Regarding the cost value (Cost) of the routing protocol, which of the following description is incorrect?
- A . Because different routing protocols use different basis for calculating routing costs, it is generally recommended to automatically switch when importing routes.
- B . Because different routing protocols have different basis for calculating routing costs, manual configuration is generally recommended when importing routes.
- C . Generally, the cost values of ISIS and OSPF are based on bandwidth, and the range of values is wide.
- D . Generally, the overhead of RIP is based on the number of hops, and the value range is very small.
By default, the SSM group range is 232.0.0.0/8. If you want to modify the SSM group range, which of the following configurations is correct?
- A . Configure ssm-policy acl-number in system view.
- B . Configure ssm-policy advanced-acl-number in system view.
- C . Configure ssm-policy acl-number in PIM view.
- D . Configure ssm-policy advanced-acl-number in PIM view.
What is the wrong description of the LSA header information in the AS-External-LSA of OSPF?
- A . Link state ID indicates the destination network address
- B . Advertising Router represents the Router ID of ASBR
- C . Net mask represents the net mask of the destination network segment
- D . Forwarding Address is always 0.0.0.0
Which of the following description of EGP and IGP is wrong
- A . IGP is a routing protocol that runs inside the AS
- B . EGP is a routing protocol running between ASs
- C . IGP focuses on controlling the propagation of routes and choosing the best route
- D . EGP itself is an ancient agreement
Which of the following description of Local-Preference is correct?
- A . Local-Preference is recognized as a mandatory attribute.
- B . Local-Preference affects the traffic entering the AS
- C . Local-Preference can be spread across AS
- D . The default value of Local-Preference is 100
Which of the following about the description of OSPF features is wrong?
- A . OSPF uses link state algorithm
- B . Each router advertises local link state information through flooding LSA
- C . Each OSPF device collects LSAs sent by other routers, and all LSAs are put together to form the link state database LSDB.
- D . The LSDBs on all routers in OSPF area 0 are the same.
- E . According to the directed graph, each router uses the SPF algorithm to calculate a shortest path tree with itself as the root, and this tree gives the route to each node in the autonomous system.
How does the COMMUNITY attribute of the route set by the routing strategy affect the route selection?
- A . It can be indirectly affected. By setting the COMMUNITY attribute of the route, the route can be classified, and then different routing-related attributes, such as LOCAL-PRE, MED, etc., can be set according to the category, so as to achieve the purpose of influencing routing
- B . It cannot be affected because the COMMUNITY attribute of the route is a non-transitional attribute and cannot be passed between routers
- C . It can be affected indirectly. By setting the COMMUNITY attribute of the route, the route can be classified, and then different routing-related attributes can be set according to the category. These attributes can only include LOCAL-PRE, MED, to achieve the purpose of influencing routing selection.
- D . After the router receives the route update with the COMMUNITY attribute of NO_ADVERTISE, it will not be published outside the local AS.
Which of the following description of OSPF message verification is wrong?
- A . The verification modes supported by AR2200 are divided into NULL SIMPLE MD5 and HMAC-MD5 according to the different methods specified in the encryption protocol.
- B . AR2200 supports two authentication methods: area verification and interface verification
- C . When regional verification methods and interface verification methods exist at the same time, regional verification is preferred
- D . Only OSPF packets that pass authentication can be accepted, otherwise, neighbors cannot be established normally
About the warning information "OSPF/2/IFAUTFAIL (OID) [1.3.6.1.2.1.14.16.2.6]:
A packet is received on a non-virtual interface from a router whose authentication key or authentication type conflicts with the local authenctication key or authenctication type. (IfIpAddress=[ip-address], AddressLessIf=[interface-index], ProcessId= [process -id], RouterId=[router-id], PacketSrc=[source-ip-address], ConfigErrorType=[error-type], PacketType=[packet-type], InstanceName=[instance-name])"
Which of the following description is wrong?
- A . It may be caused by incorrect interface verification and coordination
- B . Errors that may be caused by inconsistent HELLO time intervals
- C . The error may be caused by the subnet mask mismatch
- D . The error may be caused by the area code mismatch