Write in front
I have refreshed the question bank. As long as you remember the concepts, some questions can be written correctly in one time. There are also some things that are not easy to remember and easy to confuse. I have done some sorting.
About IGMP
IGMP: Internet Group Management Protocol. The multicast protocol runs between the host and the multicast router. Three versions: IGMPv1, v2, v3.
IGMP Snooping:
- Running at the link layer, it is a multicast constraint mechanism on Layer 2 Ethernet switches, used to manage and control multicast groups.
- The MAC multicast address table is established by monitoring the IGMP messages sent by the host.
In a multicast network environment, if IGMPv1 host and IGMPv2 router are in the same LAN, how do they work together?
- Membership reports sent by version 1 hosts will always be received by version 2 routers
- If the version 1 host exists in a specific group, the version 2 router must ignore any leave messages received during the reorganization
- Version 2 routers must set up a countdown timer associated with the group that takes into account the presence of version 1 hosts.
- Version 1 router treats IGMPV2 report as invalid IGMP message type and ignores it
- When the version 1 router acts as a valid IGMP querier, the version 2 host must send an IGMPv1 report
- When a version 2 host detects that the IGMP querier is a version 1 router, it must always respond with an IGMPvl report
Differences between versions:
- For members leaving, IGMPv2 / v3 can take the initiative to leave, while IGMPv1 cannot
- IGMPv1 does not support specific group queries, while IGMPv2 supports
- IGMPv1 message type does not include member leave message
- IGMPv2 message types include member leave messages
- IGMPv1 supports general group query
- IGMPv1 contains only two types of messages: membership query and membership report (correct)
- In the same local area network, if some IGMPv1 routers exist in the local area network, it must be mandatory to configure IGMPv1 for all routers in the subnet in order to use normally. (error)
About BGP
The route is injected into BGP through the re-issue command. The origin attribute is Incomplete
. The BGP attribute that can define a set of public destination addresses is: Community
BGP Commonly used routing strategy tools that can be used to add or delete AS paths are: ip as-path-filer
In the BGP routing rule, the priority judgment principle of the Origin attribute is: IGP> EGP> Incomplete is
used to filter routing information and set the routing attribute for the filtered routing information. Which
one of the following tools? Which of the following attributes of route-policy
must be present in the BGP Update message? Among the AS-PATH
BGP routing attributes, the recognized attributes: AS-PATH, Origin, and Local_Pref
can trigger the announcement of BGP routes without interrupting the BGP connection: refresh bgp all external
Which of the following BGP attributes are recognized Must comply with the type of attributes? Next_hop, AS-Path
MED is an optional non-transition attribute.
The Origin attributes of routes injected into BGP through the network command are: What are the attributes that IGP
BGP generally recognizes as mandatory? Origin, AS_Path, Next_hop
BGP public community attributes:no-advertised, advertised, internet
BGP recognized community attributes are: NO-EXPORT (OxFFFFFFOl), NO-ADVERTISE (OxFFFFFF02), Internet
About policy routing and routing policies
For link-state routing protocol, filtered inbound routing can actually block the link state information
is transmitted, the filtering effect can not be added to the route in the local routing table, and it can not receive the neighbor complete
whole route status information. (Wrong)
For link-state routing protocol, filtered inbound routing, link status may actually block the
transmission of status information, route filtering effect can not be added to the local routing table, and its neighbors
Can not receive complete routing status information. (wrong)
Does setting the Community property of a route through a routing policy affect routing?
It can be affected indirectly. You can classify routes by setting the community property of the route, and then
set different routing-related attributes according to the category , such as Local_Pre, MED, etc., to achieve the purpose of affecting routing.
The following description of routing strategies and policy routing is correct:
- Policy routing is mainly to control the forwarding of packets, that is, it is not necessary to forward packets according to the routing table.
- The routing strategy mainly controls the introduction, publication, and reception of routing information.
The routing tool route-policy can filter and set BGP attributes for predefined conditions, so it is often
used to define the BGPPeer strategy and is often used during the route generation period. By default, all unmatched routes are Rejected by route-policy (yes)
Both policy routing and routing strategies can affect the forwarding process of data packets, but they affect the packets in different ways.
Policy routing is policy-based forwarding. After failing, the routing table is searched for forwarding. Based on the forwarding plane, it serves forwarding policies and requires manual configuration. The routing strategy is based on the destination address forwarded by the routing table, based on the control plane, serving routing protocols and routing tables, and combined with routing protocols to complete the strategy. (Correct)
Questions about ip addresses
When using routing policy for route filtering, which of the following options
will be deny when matching the following IP-Prefix? (Multiple choice)
ip ip_prefix aa index 10 deny 0. 0. 0. 0 24 less-equal 32
ip ip-prefix aa index 20 permit 0. 0. 0. 0 0 less-equal 32
A. 1.1.1.1/24
B . 1.1.1.1/32
C. 1.1.1.1/26
Which of the following options satisfy the following ACL conditions? (Multiple choice)
"acl number 2001
rule 0 permit source 10.1.1.0 0.0.254.255
10.1.1.1/32
10.1.3.1/32
In order for normal non-directly connected EBGP neighbors to establish a connection, which of the following configurations must be included?
peer ebgp-max-hop
Which of the following options meets the following ACL conditions?
"Acl number 2001
rule 0 permit source 10.1.0.0 0"
10.1.0.0/16
When using routing policy for route filtering, which of the following options
will be deny when matching the following IP-Prefix? (Multiple choices)
ip ip-prefix aa index 10 permit 1.1.1.1 24 greater-equal 26 less-equal 32
1.1.1.1/24
1.1.1.2/16
When using routing policy for route filtering, which of the following options
will be deny when matching the following IP-Prefix? (Multiple
choices ) ip ip_prefix aa index 10 deny 1.1.1.1 24
ip ip-prefix aa index 20 permit 1.1.1.1 32
1.1.1.1/24
1.1.1.1/26
1.1.1.2/16
IPV4 stipulates the value range of SSM address, the following is the right option is
232.1.8.1/8
Command configuration topic
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?
Configure ssm-policy acl-number in PIM view
Which of the following is the command to enable IS-IS protocol on the interface
isis enable 100
With which command can you view the statistics of route calculation under the OSPF process?
display ospf spf-statistics
Which of the following LSAs spread only in a single area?
Router L5A
Network LSA
Which of the following commands can leak the route from level-2 area to level-1 area?
import-route isis level-2 into level-1
On the VRP platform, what commands can be used to check OSPF neighbors?
display ospf peer
display ospf interface
Which command can you use to view OSPF neighbor status information?
Display ospf peer
Which command can be used to view the detailed information of type 2 LSA?
display ospf Isdb network
What methods can modify the interface cost of OSPF?
- In interface view, execute the ospf cost command
- In ospf view, execute bandwidth-reference
Advertise routes to IBGP peers and configure their own address as the next hop as
peer xxxx next-hop-local
About Route-Policy
-There can be multiple nodes under a route-policy. Different node numbers are identified by sec-number,
and the relationship between the parts of different seq-number is "or" relationship. (Correct)
In IGMPV2, the destination IP of the specific group query is 224.0.0.1. (Correct)
Routing policy can have a plurality of lower nodes, different nodes with node identification numbers, each node may have a plurality of the if-match and apply clauses:
is "OR" between the different nodes
if each node under -match clause is "and" relationship
The correct description about Route-policy is:
A. A Route-policy is composed of multiple nodes, and a node can contain multiple if-match and apply clauses
. B. if-match clauses are used to define the matching conditions of the nodes, apply clauses Used to define the routing behavior through filtering.
The filtering rule relationship of C-if-match words is "AND", that is, all if-match words of this node must match.
D. The filtering relationship between Route-Policy nodes is "or", that is, as long as the filtering of a node is passed, the
Route-Policy can be passed .
Finally, I wish you all pass the exam, come on
