PCNE Implementing Hybrid Interconnectivity Practice Test 10 — 15 Questions

Question 1

Your company has a Partner Interconnect connection via a service provider that offers Layer 3 connectivity. The provider assigns an IP address on the VLAN attachment. Which VLAN attachment type should you use when creating the attachment in Google Cloud?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

PARTNER. When a service provider offers Layer 3 connectivity and assigns an IP address on the VLAN attachment, you must use the PARTNER attachment type. This type is specifically designed for Partner Interconnect with Layer 3 (routed) connections, where the provider manages the IP addressing and routing. PARTNER_PROVIDER is used for Layer 2 attachments where you assign your own IP addresses.

Answer

PARTNER_PROVIDER

Answer

VPN

Answer

DEDICATED

Question 2

Your organization uses Cloud DNS for private DNS resolution within GCP. You need to enable on-premises DNS servers to resolve GCP private zone names (e.g., myinstance.internal.example.com). Which TWO resources must you configure? (Choose two.)

Accepted Answer

Configure an inbound DNS server policy in GCP. To allow on-premises DNS servers to resolve GCP private zone names, you only need to configure an inbound DNS server policy (option C). This creates a forwarding endpoint with a Google-managed IP address in a VPC network. On-premises DNS servers must then be configured to forward queries for the private zone to that IP address. A DNS peering zone (option B) is not required because the inbound endpoint can resolve records in any private zone that is in the same project and VPC network. The other options (A, D, E) are not relevant for this use case.

Answer

Configure an outbound DNS server policy in GCP

Answer

Create a DNS peering zone in Cloud DNS that points to the on-premises DNS servers

Answer

Set up a VPN tunnel between GCP and on-premises

Answer

Create a forwarding zone in Cloud DNS

Question 3

A network engineer is configuring BGP on a Cloud Router for a Dedicated Interconnect. They want to apply traffic engineering to prefer one path over another for inbound traffic from on-premises to GCP. Which THREE BGP attributes can be used to influence this inbound traffic? (Choose three.)

Accepted Answer

BGP communities. For inbound traffic from on-premises into GCP, the engineer must influence the on-premises routers' BGP decision process, and the attributes that can be advertised from the Cloud Router to achieve this are BGP communities (A), AS path prepending (C), and MED (E). BGP communities (A) are transitive optional attributes that tag routes so the on-premises side can apply a matching routing policy to prefer or deprioritize specific prefixes. AS path prepending (C) makes a route less attractive by artificially lengthening the AS_PATH, so the remote AS prefers the shorter path for inbound traffic. MED (E) is a non-transitive optional attribute exchanged between neighboring autonomous systems that suggests a preferred entry point, letting the on-premises router choose the lower-metric path into GCP. Weight (B) is a Cisco-proprietary, locally significant attribute that is never advertised in BGP updates, so it cannot affect remote inbound path selection. Local preference (D) is also locally significant and is only propagated within an autonomous system via IBGP, so it influences outbound path selection inside GCP rather than inbound traffic from on-premises.

Answer

Weight

Answer

Local preference

Question 4

You are setting up Partner Interconnect with a service provider that offers both Layer 2 and Layer 3 options. Your on-premises network uses BGP to exchange routes. Which THREE statements are true about the connectivity types? (Choose three.)

Accepted Answer

With Layer 2 connectivity, you must configure BGP sessions between your on-premises router and Cloud Router. Option B is correct because with Layer 2 Partner Interconnect the provider only transports VLAN traffic, so the customer must establish the BGP session between the on-premises router and the Google Cloud Router over the VLAN attachment. Option C is correct because both Layer 2 and Layer 3 Partner Interconnect support dynamic routing via BGP, allowing route exchange between on-premises and Google Cloud. Option D is correct because with Layer 3 connectivity the service provider handles the BGP peering with the Cloud Router on the customer's behalf, so the customer does not configure the BGP session directly. Option A is incorrect because Layer 3 connectivity uses a VLAN attachment of type DEDICATED or PARTNER, not PARTNER_PROVIDER; PARTNER_PROVIDER is used for Layer 2. Option E is incorrect because Layer 2 connectivity uses a VLAN attachment of type PARTNER, not PARTNER_PROVIDER.

Answer

Layer 3 connectivity requires a VLAN attachment of type PARTNER_PROVIDER

Answer

Layer 2 connectivity requires a VLAN attachment of type PARTNER_PROVIDER

Question 5

You need to monitor the health and performance of a Dedicated Interconnect connection. Which THREE Cloud Monitoring metrics should you use? (Choose three.)

Accepted Answer

interconnect/network/received_bytes_count. Option A, interconnect/network/received_bytes_count, is correct because it measures the volume of bytes received over the Dedicated Interconnect and is a key throughput/health indicator for detecting traffic anomalies or drops in inbound data. Option B, interconnect/link/packets_dropped, is correct because packet drops on the link directly signal physical or congestion problems affecting the interconnect's performance and reliability. Option D, interconnect/link/operational_status, is correct because it reports whether the link is up or down, which is essential for monitoring the availability and health of the Dedicated Interconnect. Option C, interconnect/network/sent_packets_count, is not among the marked correct answers, so it is not required here. Option E, interconnect/link/latency, is also not marked correct and is not one of the three metrics to select for this scenario.

Answer

interconnect/network/sent_packets_count

Answer

interconnect/link/latency

Question 6

Your organization has a single 10-Gbps Dedicated Interconnect connection from its data center to Google Cloud. The connection has one VLAN attachment (VLAN 100) that uses a Cloud Router in the us-central1 region. The on-premises router is configured with a BGP session to that Cloud Router, and all routes are exchanged correctly. The company now requires that the connection survive a failure of the Cloud Router or a zone outage in us-central1 without any manual intervention. What should you do?

Accepted Answer

Create a new VLAN attachment on the same Dedicated Interconnect in a different region (for example, us-east1), and associate it with a Cloud Router in that region.. To survive a Cloud Router or zone failure, the VLAN attachment must terminate on a Cloud Router in a different region. A single Dedicated Interconnect can support VLAN attachments in multiple regions, each with its own regional Cloud Router. This creates independent BGP control planes and forwarding paths, allowing traffic to fail over automatically when the primary region becomes unavailable.

Answer

Create a second VLAN attachment on the same Dedicated Interconnect in the us-central1 region, and add a second Cloud Router in a different us-central1 zone to that attachment.

Answer

Replace the Dedicated Interconnect with a Partner Interconnect connection from the same data center, and use the same Cloud Router in us-central1.

Answer

Configure a second BGP session on the existing Cloud Router with a different peer IP address, and enable MD5 authentication on both sessions.

Question 7

A company has a Dedicated Interconnect connection with two VLAN attachments, each associated with a different Cloud Router in the same region. The on-premises router runs BGP and receives the same set of VPC subnet routes from both Cloud Routers. The network team wants to ensure that outbound traffic from Google Cloud to on-premises uses the VLAN attachment on Cloud Router A as the primary path and fails over to Cloud Router B only when A is unavailable. Which BGP attribute should the on-premises router manipulate, and how?

Accepted Answer

Prepend the autonomous system path on routes advertised to Cloud Router B so that Google Cloud prefers the path through Cloud Router A.. Outbound traffic from Google Cloud to on-premises follows the BGP path selected by Google Cloud based on attributes advertised by the on-premises router. AS path prepending on advertisements to Cloud Router B makes that path longer and therefore less preferred, so Google Cloud uses Cloud Router A as the primary path. If Cloud Router A becomes unavailable, the path through Cloud Router B is used automatically.

Answer

Set a higher local preference on routes advertised to Cloud Router B so that Google Cloud prefers the path through Cloud Router B.

Answer

Advertise a more specific prefix to Cloud Router B and a less specific prefix to Cloud Router A, so that Google Cloud prefers the path through Cloud Router B.

Answer

Set a higher MED value on routes learned from Cloud Router A so that Google Cloud prefers the path through Cloud Router B.

Question 8

Your organization runs a production VPC in Google Cloud with a Dedicated Interconnect connection to an on-premises data center. The on-premises network advertises a default route 0.0.0.0/0 to Cloud Router, and the VPC has no other default route. You need to ensure that traffic from VM instances uses the on-premises default route for all internet-bound traffic. What should you do?

Accepted Answer

Create a custom route on Cloud Router to import the default route from BGP, and ensure the VPC uses global dynamic routing.. Cloud Router does not accept a default route from BGP unless you explicitly create a custom route with destination 0.0.0.0/0 and next-hop the Cloud Router. Additionally, global dynamic routing ensures the learned route is available to all subnets in the VPC. This configuration allows VM instances to send internet-bound traffic through the on-premises network.

Answer

Configure a custom route advertisement on Cloud Router to advertise 0.0.0.0/0 to the on-premises network, and accept the default route from BGP.

Answer

Enable global routing mode on the VPC and add a custom static route with next-hop the on-premises router.

Answer

Create a custom dynamic routing mode on the Cloud Router to allow default route learning, and set the VPC to global routing.

Question 9

A financial services company has a Dedicated Interconnect connection between their on-premises data center and Google Cloud. They use two VLAN attachments in different metros for redundancy, each associated with a Cloud Router in the same region. The company requires that traffic from the VPC to on-premises prefer the VLAN attachment in the primary metro unless it fails. How should the network engineer configure BGP to meet this requirement?

Accepted Answer

Advertise a more specific route (longer prefix) from the primary VLAN attachment.. Cloud Router selects the best path for outbound traffic based on BGP attributes, with the longest prefix match taking precedence. By advertising a more specific prefix from the primary VLAN attachment, that path becomes preferred for destinations within that prefix. This is a reliable way to enforce egress preference without relying on MED, which affects inbound traffic.

Answer

Set a higher MED value on the primary VLAN attachment's BGP session.

Answer

Configure a higher local preference on the primary VLAN attachment's BGP session.

Answer

Set a lower MED value on the primary VLAN attachment's BGP session.

Question 10

A company's on-premises network is connected to Google Cloud via two HA VPN tunnels. The Cloud Router advertises a custom IP range 10.10.0.0/16 to on-premises, but the on-premises router receives the route with a next-hop of the Cloud Router's BGP peer address. The on-premises network uses a firewall that blocks traffic to that next-hop unless it is explicitly allowed. What should the network engineer do to ensure the on-premises firewall permits the correct next-hop?

Accepted Answer

Allow the Cloud Router's BGP peer IP address on the on-premises firewall.. The Cloud Router advertises routes to on-premises with a next-hop equal to its own BGP peer address. The on-premises firewall must allow traffic to that address for the routes to be usable. Global routing, ASN changes, or custom next-hop settings do not affect this requirement.

Answer

Configure the Cloud Router to use a custom BGP next-hop by setting the next-hop to the tunnel's internal IP address.

Answer

Enable global routing on the VPC network so that the next-hop becomes a global anycast address.

Answer

Change the BGP session to use a different autonomous system number (ASN) so that the next-hop is rewritten.

Question 11

A network engineer is deploying a Dedicated Interconnect connection between an on-premises data center and Google Cloud. The connection has two VLAN attachments in the same metropolitan area, each on a separate Cloud Router. The engineer wants to achieve 99.99% availability and ensure that a single Cloud Router failure does not disrupt traffic. What should the engineer do?

Accepted Answer

Use two separate Cloud Routers, each with its own VLAN attachment, and configure the on-premises routers to establish BGP sessions with both Cloud Routers.. To achieve 99.99% availability with Dedicated Interconnect, you must have redundant connectivity at every layer: two Dedicated Interconnect connections in different metros or two VLAN attachments in different edge availability domains, each attached to a separate Cloud Router. The on-premises routers must establish BGP sessions with both Cloud Routers. This design ensures that a single failure—whether of a Cloud Router, VLAN attachment, or physical link—does not disrupt traffic.

Answer

Configure the two VLAN attachments on the same Cloud Router and enable BGP graceful restart.

Answer

Deploy a second Dedicated Interconnect connection in the same metro and use link aggregation (LACP) to bond the two connections.

Answer

Create a single VLAN attachment with two BGP sessions to two different Cloud Routers.

Question 12

A network engineer is configuring a Cloud Router for a Dedicated Interconnect VLAN attachment. The on-premises router uses a link-local address of 169.254.10.2/30 for the BGP session, and the engineer assigns 169.254.10.1/30 to the Cloud Router interface. After the BGP session is established, the engineer notices that the on-premises router is not receiving any routes from the Cloud Router, even though the Cloud Router has learned on-premises routes. Which of the following is the most likely cause?

Accepted Answer

The Cloud Router is not configured to advertise the VPC subnets to the on-premises router.. The Cloud Router must be explicitly configured to advertise routes. By default, it advertises all subnets in the VPC network, but if custom advertisements are enabled and no ranges are specified, it advertises nothing. Since the BGP session is established and the Cloud Router learns on-premises routes, the missing advertisements point to a misconfiguration in the Cloud Router's advertisement settings. The engineer should verify that the router is either using default advertisement or has the correct custom ranges defined.

Answer

The BGP session is using IPv6 link-local addresses, which are not supported for route advertisement.

Answer

The Cloud Router is not advertising any routes because it has no VPC subnets attached to it.

Answer

The on-premises router is configured with a BGP peer that has a different autonomous system number (ASN) than the Cloud Router's ASN.

Question 13

A company is deploying a Partner Interconnect connection to connect their on-premises network to Google Cloud. They need to ensure that the connection supports the required bandwidth and that the VLAN attachment is properly configured. Which two actions must they take? (Choose two.)

Accepted Answer

Create a VLAN attachment in the Google Cloud Console and specify the pairing key provided by the service provider.. To set up Partner Interconnect, you must work with a service provider to obtain a pairing key, and then create a VLAN attachment in Google Cloud using that pairing key. These two steps are essential. Other actions like cross-connects or backup VPNs are not required for the initial deployment.

Answer

Configure a Cloud Router in the same region as the VLAN attachment.

Answer

Provision a cross-connect in a Google colocation facility.

Answer

Set up a Cloud VPN tunnel as a backup to the Partner Interconnect.

Question 14

A company has a Dedicated Interconnect connection with two VLAN attachments in different metro areas, each associated with a Cloud Router. They want to ensure that if one VLAN attachment fails, traffic automatically fails over to the other. Which two actions should they take? (Choose two.)

Accepted Answer

Set a higher local preference on the Cloud Router associated with the primary VLAN attachment.. To ensure automatic failover for outbound traffic from Google Cloud to on-premises, you need to influence BGP path selection. Setting a higher local preference on the primary Cloud Router makes it preferred; if it fails, the backup with lower local preference takes over. Alternatively, advertising routes with a longer AS path from the backup achieves the same effect. Both methods are valid for controlling outbound traffic.

Answer

Configure the on-premises routers to use the same BGP priority for both VLAN attachments.

Answer

Configure the same MED value on both Cloud Routers for all advertised routes.

Answer

Enable global routing on the VPC to allow failover between regions.

Question 15

A network engineer is configuring a Dedicated Interconnect connection with two VLAN attachments in different metropolitan areas for redundancy. The engineer wants to ensure that if one VLAN attachment fails, traffic automatically shifts to the other. Which BGP configuration should be used on the Cloud Routers to achieve this?

Accepted Answer

Configure each VLAN attachment with its own Cloud Router in the respective region and use BGP route priorities with a lower MED on the primary attachment.. For redundant Dedicated Interconnect attachments in different metros, each attachment must use a Cloud Router in its own region. To achieve failover, set a lower MED on the primary attachment so that on-premises prefers it. When the primary fails, the higher MED on the secondary makes it the next best path.

Answer

Configure each VLAN attachment with its own Cloud Router in the respective region and set a higher MED on the primary attachment.

Answer

Configure both VLAN attachments to use the same Cloud Router and set the same MED on both BGP sessions.

Answer

Configure both VLAN attachments to use the same Cloud Router and enable BGP multipath.