Juniper JN0-664 Service Provider Routing and Switching, Professional Exam JNCIP-SP Exam Practice Test

Answer : A, B

In the provided exhibit, the output of the `show pim join extensive 232.1.1.1` command is shown. This command provides detailed information about the PIM join state for the specified multicast group (232.1.1.1) on the router R1. To determine the correct statements regarding the multicast traffic, let's analyze the output and the terms involved:

1. **ASM vs. SSM**:

- **ASM (Any-Source Multicast)**: In ASM, receivers are interested in receiving multicast traffic from any source sending to a particular multicast group.

- **SSM (Source-Specific Multicast)**: In SSM, receivers are interested in receiving traffic only from specific sources for a multicast group.

- **Group Address Range**:

- ASM uses the range 224.0.0.0 to 239.255.255.255.

- SSM uses the range 232.0.0.0 to 232.255.255.255.

Since the group address 232.1.1.1 falls within the SSM range (232.0.0.0/8), there might be confusion. However, considering the flags and states in the output, it's evident that the PIM mode and source information are consistent with ASM behavior.

2. **Multicast Trees**:

- **RPT (Rendezvous Point Tree)**: Multicast traffic initially uses the RPT, where the Rendezvous Point (RP) acts as an intermediate point.

- **SPT (Shortest Path Tree)**: After the initial join via RPT, traffic can switch to SPT, which is a direct path from the source to the receiver.

3. **Output Analysis**:

- **Flags**:

- The flags `sparse, rp-tree, wildcard` indicate that the group 232.1.1.1 is currently using RPT. This is typical for ASM, where traffic initially goes through the RP.

- The flags `sparse, spt` indicate that for the source 172.16.1.2, traffic has switched to SPT, meaning it is using the shortest path from the source directly to the receivers.

**Conclusion**:

Based on the analysis:

- **A. The multicast group is an ASM group**: This statement is correct as the configuration and behavior indicate ASM operation.

- **B. The multicast traffic is using the SPT**: This statement is also correct because the flags for the source 172.16.1.2 indicate that the traffic is using the SPT.

Thus, the correct answers are:

**A. The multicast group is an ASM group.**

**B. The multicast traffic is using the SPT.**

**Reference**:

- Juniper Networks PIM Documentation: [PIM Overview](https://www.juniper.net/documentation/en_US/junos/topics/concept/pim-overview.html)

- Junos OS Multicast Routing Configuration Guide: [Multicast Routing Configuration Guide](https://www.juniper.net/documentation/en_US/junos/topics/topic-map/multicast-routing.html)

Answer : A

In the context of Layer 3 VPNs (L3VPN) using MPLS, the routing information for different customers (VPNs) is typically stored in separate routing tables (VRFs). When you want to verify that PE2 is receiving the VPN routes for Customer C from PE1, you need to check the appropriate VRF routing table on PE2.

1. **Option A: show route table customer-c.inet.0**

- This command displays the routing table specific to Customer C's VRF.

- Since we want to verify that PE2 has received the VPN routes for Customer C, this is the most appropriate command to use.

- It allows us to see all routes learned for Customer C's VPN.

2. **Option B: show route table bgp.l3vpn.0**

- This command displays the BGP routing table for all L3VPN routes.

- While this includes routes for Customer C, it also includes routes for all other VPNs, making it harder to isolate the specific information for Customer C.

- This command is more useful for an overall view of BGP L3VPN routes rather than for a specific customer's VRF.

3. **Option C: show route summary**

- This command provides a summary of the routes in all routing tables.

- It doesn't give detailed information about the specific routes for Customer C's VRF.

- It's useful for a high-level overview but not for verifying specific customer routes.

4. **Option D: show route table inet.0**

- This command shows the global routing table, not the VRF-specific tables.

- The global routing table doesn't contain the VPN-specific routes that are stored in the VRF tables.

- Therefore, it won't help in verifying the routes for Customer C.

**Conclusion**:

To verify that PE2 is receiving VPN routes for Customer C from PE1, the most appropriate command is to check the specific VRF routing table for Customer C. Hence, the correct answer is:

**A. show route table customer-c.inet.0**

**Reference**:

- Junos OS documentation on MPLS VPNs: [Junos MPLS VPNs Guide](https://www.juniper.net/documentation/en_US/junos/topics/topic-map/mpls-vpns.html)

- Command Reference for Routing Tables: [Junos OS Routing Tables Command Reference](https://www.juniper.net/documentation/en_US/junos/topics/reference/command-summary/show-route-table.html)

Answer : B

To allow Site 1 to access three VLANs that are located in Site 2 and Site 3, you need to configure three L2VPN routing instances on PE-1, one for each VLAN. Each L2VPN routing instance will have a different VLAN ID and a different VNI for VXLAN encapsulation. Each L2VPN routing instance will also have a different vrf-target export value to identify which VPN routes belong to which VLAN. This way, PE-1 can forward traffic from Site 1 to Site 2 and Site 3 based on the VLAN tags and VNIs.

Answer : B, C

This is an EVPN Type-2 route, also called a MAC/IP advertisement route, that is used to advertise host IP and MAC address information to other VTEPs in an EVPN network. The route type field in the EVPN NLRI has a value of 2, indicating a Type-2 route. The device advertising this route into EVPN is 192.168.101.5, which is the IP address of the VTEP that learned the host information from the local CE device. This IP address is carried in the MPLS label field of the route as part of the VXLAN encapsulation.

Answer : B, C, D

To create a summary route for IS-IS, you need to configure a policy statement that matches the prefixes to be summarized and sets the next-hop to discard. You also need to configure a summary-address statement under the IS-IS protocol hierarchy that references the policy statement. In this case, the policy statement leak-v6 is trying to match the prefix 2001:db9:a:fa00::/61 exactly, but this prefix is not advertised by any router in the network. Therefore, no summary route is created. To fix this, you need to delete the longer keyword from the route-filter term and change the prefix length to /61 exact. This will match any prefix that falls within the /61 range. You also need to delete the export statement under protocols isis, because this will export all routes that match the policy statement to other IS-IS routers, which is not desired for a summary route.

Answer : C

The vrf-target export parameter is used to specify one or more BGP extended community attributes that are attached to VPN routes when they are exported from a VRF routing instance to remote PE routers. This parameter allows you to control which VPN routes are accepted by remote PE routers based on their import policies. You can specify more than one vrf-target export value for a VRF routing instance to support advanced route filtering or route leaking scenarios.

Answer : D

The attached bit is a flag in an IS-IS LSP that indicates whether a router is connected to another area or level (L2) of the network. By default, L2 routers set this bit when they advertise their LSPs to L1 routers, and L1 routers use this bit to select a default route to reach other areas or levels through L2 routers. However, this may result in suboptimal routing if there are multiple L2 routers with different paths to other areas or levels. To ensure that L1 routers have only the most specific routes available from L2 routers, you can configure the ignore-attached-bit parameter on all L1 routers. This makes L1 routers ignore the attached bit and install all interarea routes learned from L2 routers in their routing tables.