Exhibit
R4 is directly connected to both RPs (R2 and R3) R4 is currently sending all ,o,ns upstream to R3 but you want all joins to go to R2 instead Referring to the exhibit, which configuration change will solve this issue?
Correct Answer:
A
PIM Bootstrap Router (BSR) is a mechanism that allows PIM routers to discover and announce rendezvous point (RP) information for multicast groups. BSR uses two roles: candidate BSR and candidate RP. Candidate BSR is the router that collects information from all available RPs in the network and advertises it throughout the network. Candidate RP is the router that wants to become the RP and registers itself with the BSR. There can be only one active BSR in the network, which is elected based on the highest priority or highest IP address if the priority is the same. The BSR priority can be configured manually or assigned automatically. The default priority is 0 and the highest priority is 2515. In this question, R4 is directly connected to both RPs (R2 and R3) and is currently sending all joins upstream to R3 but we want all joins to go to R2 instead. To achieve this, we need to change the BSR priority on R2 to be higher than R3 so that R2 becomes the active BSR and advertises its RP information to R4.
Reference: 1: https://study-ccnp.com/multicast-rendezvous-points-explained/
Which two statements are correct about reflecting inet-vpn unicast prefixes in BGP route reflection? (Choose two.)
Correct Answer:
AB
Route reflection is a BGP feature that allows a router to reflect routes learned from one IBGP peer to another IBGP peer, without requiring a full-mesh IBGP topology. Route reflectors do not change any existing BGP attributes by default when advertising routes, unless explicitly configured to do so. A BGP peer does not require any configuration changes to become a route reflector client, only the route reflector needs to be configured with the client parameter under [edit protocols bgp group group-name neighbor neighbor- address] hierarchy level.
Which two statements are correct about a sham link? (Choose two.)
Correct Answer:
AC
A sham link is a logical link between two PE routers that belong to the same OSPF area but are connected through an L3VPN. A sham link makes the PE routers appear as if they are directly connected, and prevents OSPF from preferring an intra-area back door link over the VPN backbone. A sham link creates an OSPF multihop neighborship between the PE routers using TCP port 646. The PEs exchange Type 1 OSPF LSAs instead of Type 3 OSPF LSAs for the L3VPN routes, which allows OSPF to use the correct metric for route selection1.
Exhibit
Based on the configuration contents shown in the exhibit, which statement is true?
Correct Answer:
D
BGP policy framework is a set of tools that allows you to control the flow of routing information and apply routing policies based on various criteria. BGP policy framework consists of several components, such as route maps, prefix lists, community lists, AS path lists, and route filters. Route maps are used to define routing policies by matching certain conditions and applying certain actions. Prefix lists are used to filter routes based on their prefixes. Community lists are used to filter routes based on their community attributes. AS path lists are used to filter routes based on their AS path attributes. Route filters are used to filter routes based on their prefix length or range3. In this question, we have a route map named ISP-A that has two clauses: clause 10 and clause 20. Clause 10 matches any route with a prefix length between 8 and 24 bits and sets the local preference to 200. Clause 20 matches any route with a prefix of 224.7.7.7/32 and rejects it. The route map is applied inbound on the BGP neighborship with ISP-A. Based on this configuration, the correct statement is that joins for group 224.7.7.7 are always rejected, regardless of the group count. This is because clause 20 explicitly denies any route with a prefix of 224.7.7.7/32, which corresponds to the multicast group 224.7.7.7.
Reference: 3: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/configuration/xe-16/irg-xe-16-book/bgp-policy-framework.html
Exhibit
The network shown in the exhibit is based on IS-IS Which statement is correct in this scenario?
Correct Answer:
A
IS-IS is an interior gateway protocol that uses link-state routing to exchange routing information among routers within a single autonomous system. IS-IS uses two types of addresses to identify routers and areas: system ID and area address. The system ID is a unique identifier for each router in an IS-IS domain. The system ID is 6 octets long and can be derived from the MAC address or manually configured. The area address is a variable-length identifier for each area in an IS-IS domain. The area address can be 1 to 13 octets long and is composed of high-order octets of the address. An IS-IS instance may be assigned multiple area addresses, which are considered synonymous. Multiple synonymous area addresses are useful when merging or splitting areas in the domain1. In this question, we have a network based on IS-IS with four routers (R1_1, R1_2, R2_1, and R2_2) belonging to area 0001. The area address for area 0001 is 49.0001. The NSEL byte for area 0001 is the last octet of the address, which is 01. The NSEL byte stands for Network Service Access Point Selector (NSAP Selector) and indicates the type of service requested from the network layer2. Therefore, the correct statement in this scenario is that the NSEL byte for area 0001 is 01.
References: 1: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_isis/configuration/xe-16/irs-xe-16-book/irs-ovrvw-cf.html 2:
https://www.juniper.net/documentation/us/en/software/junos/is-is/topics/concept/is-is-routing-overview.html
