Download Implementing Cisco Enterprise Advanced Routing and Services (300-410 ENARSI).300-410.VcePdf.2021-07-15.76q.vcex

The newest OSPFv3 configuration approach utilizes a single OSPFv3 process. It is capable of supporting IPv4 and IPv6 within a single OSPFv3 process. OSPFv3 builds a single database with LSAs that carry IPv4 and IPv6 information. The OSPF adjacencies are established separately for each address family. Settings that are specific to an address family (IPv4/IPv6) are configured inside that address family router configuration mode. Running single OSPFv3 for both IPv4 and IPv6 is supported since Cisco IOS Software Release 15.1(3)S. The new-style OSPFv3 process is enabled using the router ospfv3 process-number command. Within the OSPF process configuration mode, the OSPF process ID is defined (using the router-id ospf-process-ID command). OSPFv3 New-Style OSPF Configuration Commands:R1(config)#ipv6 unicast-routing //although only OSPFv3 for IPv4 is configured but we have to enable IPv6 under global configuration mode R1(config)#router ospfv3 1 R1(config-router)# router-id 1.1.1.1 R1(config)#interface GigabitEthernet0/1 R1(config-if)#ipv6 enable //although only OSPFv3 for IPv4 is configured but we have to enable IPv6 under interface mode R1(config-if)#ospfv3 1 ipv4 area 0 Therefore answer B is the best answer here but in this answer, the configuration mode is not correct. It should be interface mode (config-if)#, not router mode (config-router)#. Reference: https://www.ciscopress.com/articles/article.asp?p=2294214&seqNum=4

In the output of R1, we see R1 has a default route to the Internet via G1/0, which is correct but R2 does not have this route. One reasonable answer of this issue is R1 has been configured as a stub router so it only advertised connected and summary routes. In Branch router output, we also see routes that are directly connected to R1 only. Note: In this topology, only Branch router should be configured as stub, not R1 router.

The AD of static route is manually configured to 130 which is higher than the AD of OSPF router which is 110.

The summary-address is only used to create aggregate addresses for OSPF at an autonomous system boundary. It means this command should only be used on the ASBR when you are trying to summarize externally redistributed routes from another protocol domain or you have a NSSA area. But a requirement to create a summarized route is:The ASBR compares the summary route's range of addresses with all routes redistributed into OSPF on that ASBR to find any subordinate subnets (subnets that sit inside the summary route range). If at least one subordinate subnet exists, the ASBR advertises the summary route. Reference: CCNP Route 642-902 Official Certification GuideBut in this case we found no prefix that belongs to 10.0.0.0/8. Therefore a summarized route for this subnet could not be created. Note:If a prefix of this subnet exists in the routing table then after the summarization is performed, we will see such an entry:Router# show ip route -- output omitted -- 0 10.0.0.0/8 is a summary via null0 An example of using the command summary-address is shown below:        Recently the RIPv2 domain has been redistributed into our OSPF domain but the administrator wants to configure a summarized route instead of 32 external type-5 LSAs (for 172.16.32.0/24 to 172.16.63.0/24) flooding into the OSPF network. In this case the administrator has to use the summary-address command as follows:Router(config-router)#summary-address 172.16.32.0 255.255.224.0 Note: In this case R1 is the ASBR for OSPF domain.BGP Questions https://www.networktut.com/bgp-questions

With route reflector (RR), we only need to establish a BGP session from the RR to each internal peer -> Answer A is not correct. We can advertise both classful and classless prefix to other clients, provided that the prefix satisfies the RR forwarding rules -> Answer B and answer C are not correct. Therefore only answer D is left. Maybe we are missing an IGP in our topology so R2 did not know how to reach the next hop reported by the prefix.

The conform-action specifies the action to take on packets that conform to the rate limit and the exceed-action specifies the action to be taken on packets when the packet rate is greater than the rate specified in the maximum-burst-bytes argument.

Idle (PfxCt) means the session is in the Idle state because the neighbor has sent more prefixes than the configured maximum-prefixes limit. router bgp 100 neighbor 10.0.0.1 remote-as 200 neighbor 10.0.0.1 maximum-prefix 10 80 In the last command, 10 is the maximum number of prefixes allowed from the neighbor and the router starts to generate a warning message at 80%. Reference: https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/25160- bgp-maximum-prefix.htmlTherefore if the BGP neighbor sent 11 prefixes, the local router will be in Idle (PfxCt) state. Route-map Questions https://www.networktut.com/route-map-questions

AS-Path prepending is a way to manipulate the AS-Path attribute of a BGP route. It allows prepending multiple entries of AS to a BGP route.