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Analyzing BGP Route Information:

The exhibit shows BGP route information for the prefix 203.0.113.0/24.

Both paths to this prefix are learned from the same BGP peer with IP address 192.168.10.36.

Understanding BGP Neighbors:

The presence of multiple paths for the same prefix does not necessarily indicate multiple neighbors.

In this case, the routes to 203.0.113.0/24 are both learned from a single neighbor (192.168.10.36), but via different interfaces (ae8.0 and ae7.0).

Conclusion:

The BGP routes in the exhibit indicate that the prefix is learned from one neighbor but via different interfaces.

References:

BGP route analysis

Understanding BGP multi-path and neighbor relationships

Understanding the Configuration:

The provided configuration and output snippets show how traffic is classified and assigned to different forwarding classes based on the IP precedence values.

The inet-precedence classifier maps specific IP precedence values to forwarding classes with associated loss priorities.

Review of Classifiers:

IP Precedence Value 100:

The IP precedence value 100 in binary is represented as 100 (binary for 4).

Matching with Classifiers:

According to the configuration shown in the exhibit:

classifiers {

inet-precedence cos;

}

The classifier cos maps the following:

forwarding-class expedited-forwarding;

loss-priority low code-points 100;

Conclusion:

The IP precedence value 100 matches the expedited-forwarding forwarding class with low loss-priority as per the configuration.

The address range 232.0.0.0/8 is reserved for Source-Specific Multicast (SSM). This range is specifically allocated for SSM where data is sent from a specific source to the receivers.

References:

Source-Specific Multicast (SSM) Overview, RFC 4607

Area-1 has no external connections. However, Area-1 has static route (172.16.31.0/24) that are not internal OSPF route. You can limit the external route advertisements to the area and advertise the static routes by designating the area an NSSA. In an NSSA, the ASBR (vMX1) generates NSSA external (Type 7) LSAs and floods them into the NSSA, where they are contained. Type-7 LSAs allow an NSSA to support the presence of ASBR and their corresponding external routing information. The ABR (vMX2) converts Type-7 LSAs into Type-5 External LSAs and leaks them to the other areas, but external routes from other areas are not advertised within the NSSA. An admin should check this and change it https://www.packetswitch.co.uk/configuring-junos-ospf-stub-and-nssa-areas/ https://www.juniper.net/documentation/us/en/software/junos/ospf/topics/ref/statement/nssa-edit-protocols-ospf.html

The correct sequence for BGP active route selection when BGP multipath or multihop are not configured is as follows:

Higher local preference: Routes with a higher local preference are preferred.

Shortest AS path: Routes with the shortest AS path are preferred.

Lower origin code: Routes with lower origin code (IGP < EGP < Incomplete) are preferred.

Lowest router ID: Routes with the lowest router ID are preferred.

Lowest peer address: Routes with the lowest peer address are preferred.

References:

Standard BGP route selection criteria as outlined in network routing protocols.

Documentation from "Useful Juniper Commands.txt" and "Juniper Commands.pdf" which include detailed BGP operational commands and preferences​​​​.

From the provided IS-IS adjacency outputs:

R1 is configured to participate in both Level 1 and Level 2 (A): This is indicated by the adjacency states for both Level 1 and Level 2 on the R1 interfaces.

R2 is configured to participate in Level 2 only (D): This is shown by the adjacency state for Level 2 only on the R2 interfaces.

References:

The IS-IS adjacency outputs indicate the state and levels of participation for each router.

Configuration and command references from "Example configs for VMRCAXP01W.txt" and other documents provide context for understanding IS-IS states and levels​​​​​​.

Step 1: Identify the requirement.

You need an OSPF area that only contains intra-area route information in the form of Type 1 and Type 2 LSAs.

Step 2: Analyze the possible OSPF area types.

Option A: Totally non-to-stubby area.

Option B: Totally stubby area.

Option C: Stub area.

Option D: Non-to-stubby area.

Step 3: Understand OSPF area types.

Totally Stubby Area (Option B): Only allows Type 1 and Type 2 LSAs and blocks Type 3, 4, and 5 LSAs. It uses a default route to represent external routes.

This fits the requirement of containing only intra-area routes.

References:

Juniper OSPF configuration guide on area types​​​​.

Commands for configuring a totally stubby area:

shell

Copy code

set protocols ospf area <area-id> stub no-summaries

"Secondary interfaces are supported for LAN interfaces (the primary interface can be a LAN interface, but any secondary interfaces are treated as point-to-point unnumbered links over the LAN). In this scenario, you must ensure that there are only two routing devices on the LAN or that there are only two routing devices on the LAN that have secondary interfaces configured for a specific OSPF area." [https://www.juniper.net/documentation/us/en/software/junos/ospf/topics/topic-map/configuring-ospf-areas.html#id-example-configuring-multiarea-adjacency-for-ospf]