Juniper Service Provider Routing and Switching, Specialist JN0-363 JNCIS-SP Exam Questions

Answer : A, B

https://zartmann.dk/sr-intro/

In segment routing, SIDs (Segment Identifiers) are used to identify different types of segments that can be traversed. A node SID represents an instruction to route a packet to a particular node, and an adjacency SID represents an instruction to route a packet over a specific link or adjacency between two nodes.

Juniper Networks Technical Documentation on Segment Routing

Answer : B

In the OSPF routing table output, prefixes are marked with different route types. An external prefix injected into OSPF is marked as 'Ext' (External) followed by a number that indicates whether it's an E1 or E2 route. The prefix 172.18.1.0/24 is marked as Ext2, which indicates that it is an external route that has been redistributed into OSPF from another routing protocol or static configuration.

Juniper Networks Technical Documentation on OSPF

Answer : A, B, E

https://www.catchpoint.com/bgp-monitoring/bgp-attributes

BGP Attribute Categories

There are four categories of BGP attributes:

Well-known mandatory:Recognized by all BGP peers, passed to all peers, and present in all Update messages. Well-known mandatory attributes include:- Next-hop- Origin- AS PATH

Well-known discretionary:Recognized by all routers, passed to all peers, and optionally included in the Update message. Well-known discretionary attributes include:- Local Preference- Atomic Aggregate

Optional transitive:Possibly recognized by BGP routers and passed to BGP peers. Optional transitive attributes are marked as partial when not recognized. Optional transitive attributes include:- Aggregator- Community

Optional non-transitive:Possibly recognized by BGP routers but not passed to peers. Optional non-transitive attributes include:- Multi-exit discriminator (MED)- Originator ID- Cluster-ID

The three well-known mandatory BGP attributes that must be present in every BGP update message are:

Next Hop: Indicates the next hop IP address to reach the advertising BGP peer.

Origin: Indicates how the route was originated, whether it was via IGP, EGP, or incomplete.

AS Path: Lists the autonomous systems that the update has traversed.

Juniper Networks Technical Documentation on BGP Attributes

Answer : A, B

Segment routing is a source routing paradigm that allows a source router to define the path that a packet will take through the network by assigning an ordered list of segments---identifiers that specify a forwarding path for the packet through the network. Segment Routing can be implemented over an MPLS architecture or with IPv6 (SRv6).

A . Segment routing does not require a full mesh of adjacencies or state per transit path in the network, which is often the case with conventional MPLS signaling protocols like RSVP-TE. It leverages the existing IGP topology for forwarding without the need to maintain a state for each LSP (Label Switched Path), hence requiring very little resources to maintain.

B . In segment routing, labels (or segments) are distributed via IGP routing protocols like OSPF or IS-IS with extensions to carry segment routing information. These protocols are enhanced with Segment Routing extensions to distribute labels. For example, OSPFv2 is extended with Segment Routing extensions defined in RFC 8665.

C . This statement is not entirely correct. While it is true that segment routing does not require the maintenance of a state for each path (LSP), the concept of 'segment routing adjacencies' is a mischaracterization. Segment routing leverages the existing adjacencies formed by the underlying IGP.

D . Label assignments in segment routing are not advertised through LDP (Label Distribution Protocol) updates. Segment routing does away with LDP and instead uses IGP extensions to distribute labels.

Juniper Networks documentation on Segment Routing: Segment Routing Overview

Juniper Networks technical documentation providing guidance on configuring OSPF with Segment Routing extensions.

IETF RFC 8665: OSPF Extension for Segment Routing.

Answer : A

https://www.networkfuntimes.com/junos-aggregate-routes-vs-generate-routes-how-to-summarise-on-juniper-routers/

Generated routes are a type of route that can be created to summarize and generate more specific routes within the routing table. Unlike aggregate routes, which summarize existing routes and inherit a next-hop, generated routes do not necessarily have to match an existing route and will have a next-hop of reject by default unless specified otherwise.

Juniper Networks Technical Documentation on Routing Policies and Route Generation

Answer : B, D

static route with a next-hop of next-table pointing to the appropriate routing table which contains more accurate information rib-groups to mirror routing information from one route-table to another. However, in many cases, in order to make this work, interface-routes also need to be mirrored. RIB Group policy can be used to constrain the routing information instance-import and instance-export statements configured within the individual routing-instances to leak routes from one table to another. Again, policy can be used here to constrain the routing information. This method is more straightforward than the rib-group method A final approach is to use physical interfaces or logical-tunnels to stitch routing-instances and use a routing protocol or static routes across this connection between the two routing-instances.

To share routes between two routing instances on a Junos device, you can configure an instance import policy in one or both instances to import routes from the other instance. Alternatively, a RIB (Routing Information Base) group can be used to share routes between instances. Reference::

Routing Instances Overview, Juniper Networks Documentation

RIB Groups Configuration Guide, Juniper Networks Documentation

Answer : B

To verify the status of the tunnel from R1, you would issue a ping from the source address that is assigned to R1's end of the tunnel. In the exhibit, we can see that the tunnel interface (gre-0/0/0.0) has the IP address 198.51.100.1 on R1. Therefore, to test the tunnel's status, you should ping the IP address at the other end of the tunnel (which is likely the address on User B's interface or another interface on R2) from R1's tunnel source address.

Juniper Networks documentation on GRE: GRE Interface Configuration