4A0-106 Nokia Virtual Private Routed Networks Questions and Answers

Customer carrier PE routers residing in different sites must run iBGP between them to exchange customers ' routes.

MPLS can be used in the customer carrier network to improve scalability.

The customer carrier network can be a pure IP network.

A CSC VPRN is configured on the CSC-CE to forward data packets to the network provider.

The ability to offer Internet connectivity and a variety of services over a single CSC VPRN interface.

The ability to maintain its own backbone.

The ability to learn system addresses of network provider PEs.

There is no need to manage end-customer services.

PE2 pushes one label on the IP packet and forwards it to ASBR2.

ASBR2 sends the IP packet with one label to ASBR1.

ASBR1 sends the IP packet with one label to PEL

PE1 pops one label off the IP packet and forwards it to CE1.

Three route targets and three route distinguishers

Five route targets and three route distinguishers

Three route targets and two route distinguishers

Five route targets and two route distinguishers

Logical Partitioning of route reflectors works best when PEs are partitioned to support different VPRNs.

Logical Partitioning of route reflectors is simple and scalable, but requires more hardware.

Filtering at route reflectors requires either inbound filtering at the route reflector or outbound filtering at the PE routers.

Filtering at route reflectors allows the route reflector to filter routes received from PEs and only accept routes with a certain route distinguisher.

Show router bgp routes

Show router bgp routes address-family vpn-ipv4

Show router bgp routes < service-id >

Show router < service-id > bgp routes

PE1 sends an IPv4 update for prefix 192.168.1.0/27 via MP-BGP to ASBR1.

ASBR1 sends an IPv4 update for prefix 192.168.1.0/27 to ASBR2.

ASBR1 transforms an IPv4 update for prefix 192.168.1.0/27 to a VPN-IPv4 route; allocates VPN label V1 and sends the update to ASBR2.

ASBR2 accepts a VPN-IPv4 update from ASBR1, then sends the update to PE2 via MP-BGP.

The routes to be shared are identified by common route targets

The routes to be shared are identified by common route distinguishers

The routes to be shared are identified by common AS numbers

The routes to be shared are identified by common VPN labels

ecmp and multipath must be configured within the VPRN instance.

The RD of the VPRN on the local PE must be different from the RD of the remote PEs.

Is enabled in the config > router > bgp context

Allows a PE router to load share traffic across routes learned from both direct CE-PE peerings and MP-BGP peerings.

When the route is first received at the P from the PE

When the route from the CE is populated into the VRF at the PE

When the route from the PE is populated into the VRF at the CE

When the route is propagated from the PE to the CE

When the route is exported into the MP-BGP table from the VRF

the configuration is complete and correct.

' as-override ' should be configured under the BGP context.

' as-override ' should be configured under the group context.

' as-override ' should not be part of this configuration.

Each customer site has a logically direct route to every other customer site.

It provides optimal routing between all sites.

It allows access between all CE devices and all sites participating in the same VRF.

It requires a full BGP mesh in the provider core.

“Spoke_Sites”

“Hub_Site”

“Spoke_Sites” and “Hub_Site”

No communities should be imported.

Based on the interface on which they are received.

Based on the Route Distinguisher.

Based on the Route Target.

Based on the Service Identifier.

It is located in an Autonomous System directly connected to this router

There is a single Autonomous System between the local AS and the AS that originated the prefix

There are two Autonomous Systems between the local AS and the AS that originated the prefix

There may be two or more Autonomous Systems between the local AS and the AS that originated the prefix

It is located in Autonomous System 65100

Show service id < service-id > base

Show router bgp < service-id > routes

Show service id < service-id > maximum-routes

Show router < service-id > status

PE1 sends the data packet with three labels: the bottom label is a service label, the middle label is a BGP label, and the top label is an LDP label.

ASBR1 sends the data packet with one label: the BGP label.

ASBR1 sends the data packet with one label: the service label.

ASBR2 sends the data packet with three labels: the bottom label is a service label, the middle label is a BGP label, and the top label is an LDP label.

PE1 advertises the Red VPN routes and a default route to PE3.

The Internet VRF on PE3 imports the Red VPN routes advertised by PE1.

PE1 imports all Internet routes and advertises them to CE1 via the Red VRF.

PE3 advertises a default route from its Internet VRF instead of advertising all Internet routes.

End-customer routes are populated in the network provider CSC VRF.

The customer carrier does not learn any network provider internal routes.

The network provider learns customer carrier PE system addresses.

Routes exchanged between the customer carrier and the network provider are labeled.

All traffic exchanged between end-customers is carried over a single CSC VRF.

Customer carrier PE routers residing in different sites must run eBGP between them to exchange customers ' routes.

The customer carrier network can be a pure IP network.

MPLS can be used in the customer carrier network to improve scalability.

The As-Path is not present as it was removed with the s-override configuration command

The As-Path is not present as it was removed with the o-as-path configuration command

The As-Path is not present as a policy was configured to set it to the null value

The As-Path is not present as VPN-IPv4 routes do not propagate the IPv4 As-Path BGP attribute

The customer carrier network can be a pure IP network.

The customer carrier provides Layer 2 and Layer 3 services to its end-customers.

A single CSC VPRN is configured on the network provider to support all services offered by the customer carrier.

In the case where the customer carrier offers VPRN services, the model is referred to as hierarchical VPRN.

To limit the number of routes advertised from a customer site

To limit the number of routes learned from other customer sites CTo limit the size of the VRF table

To limit connectivity to selected customer networks

To perform packet filtering

A P router may forward customer packets to their destination without the presence of a route to that destination

The ingress PE router may forward customer packets to their destination without the presence of a route to that destination

The egress PE router may forward customer packets to their destination without the presence of a route to that destination

Any provider core router (P or PE) may forward customer packets to their destination without the presence of a route to that destination

It is the customer responsibility to ensure their address space is unique

The Route Distinguisher ensures that addresses are unique between customers.

The Route Target ensures that addresses are unique between customers

The provider will advise the customers to change their addresses

The provider will use NAT to ensure that addresses are unique between customers

Show service all

Show service id < service-id > detail

Show service id < service-id > base

Show service id < service-id > bindings

Show service sap-using

Show router bgp routes

Show router bgp routes < prefix > detail

Show router route-table

Show router < service-id > route-table

Either (b) or (d)

Identify the egress PE in the MPLS domain

Signal the egress VPRN ID

Identify the ingress PE in the MPLS domain

Transport route updates between PEs

eBGP is used for route and label exchange between CSC-CE and CSC-PE routers.

iBGP can be used to distribute routes between CSC-CE and PE routers.

MP-iBGP is used to advertise routes between the CSC-PE routers.

MP-iBGP is used to advertise end-customer and Internet routes directly between the PE routers.

VPN-IPv4 routes for all PE system addresses in AS 1000

BGP labeled IPv4 routes for all PE system addresses in AS 1000

VPN-IPv4 routes for all PE system addresses in AS 5000

BGP labeled IPv4 routes for all PE system addresses in AS 5000

When sites of different VPRN customers use the same BGP AS number

When sites of the same VPRN customer use the same BGP AS number

When sites of different VPRN customers use different BGP AS numbers

When sites of the same VPRN customer use different BGP AS numbers

When the customer site AS number is the same as the provider AS number

One VPRN, one route distinguisher, and two route targets

Two VPRNs, one route distinguisher, and three route targets

Two VPRNs, two route distinguishers, and three route targets

One VPRN, two route distinguishers, and three route targets

OSPF is not configured on the CE router

There is a problem with OSPF authentication

The operational MTU does not match

The PE and CE router have different OSPF interface types configured

None of the above

Allow routes to be exchanged between all or selected sites of one VPRN and all or selected sites of a second VPRN

Allow the service provider to provide multiple VPRNs with Internet access

Reduce the number of VPRN tunnels required

Simplify the administration of multiple VPRNs

Force all traffic in multiple VPRNs to pass through a single device

One label per route

One label per next-hop

One label per VRF

One label per prefix

One label per tunnel

The route-distinguisher value must be 64496:10 for successful VPRN operation.

An export policy is not required for successful VPRN operation.

The " family vpn-ipv4 " command is required under the BGP configuration for successful VPRN operation.

The neighbor address should be 10.10.10.4 under the BGP configuration for successful VPRN operation.

The VPRN configuration on ASBR1 is correct.

To reduce the number of VPRN tunnels required.

To allow routes to be exchanged between all, or selected, sites of one VPRN, and all, or selected, sites of a second VPRN.

To simplify the administration of multiple VPRNs.

To allow network access between the headquarter sites of each VPRN service and a shared VPRN service offered by a third party.

Static

RIP

OSPF

IS-IS

MP-BGP

BGP

OSPF

ISIS

MP-BGP

BGP

Targeted LDP

On the CE under the RIP context

On the PE under the BGP context

On the PE under the RIP context

On the CE under the BGP context

This policy is not required

This configuration is correct and complete

This configuration is correct except that the system interface must be added

This configuration is correct except that the interfaces facing the CE routers must be added.

MPLS configuration is not required

PE1 pushes three labels on the IP packet: a VPN label, a BGP label, and an LDP transport label.

ASBR1 pops the LDP label, swaps the BGP label and forwards the IP packet to ASBR2.

ASBR2 swaps the BGP label and pushes an LDP transport label.

PE2 pops all labels and forwards the unlabeled packet to its destination.

It is best used when a single VPN is required to provide Internet access, as well as to maintain VPN connectivity between different customer sites.

If there is no requirement for the VRF to contain the full Internet routing table, a default route to the Internet gateway router is sufficient.

Only one interface on the CE is required for both VPN and Internet connectivity.

The Nokia 7750 SR supports route leaking in full mesh and extranet VPRN topologies only.

target:65100:2 and target:65100:3

target:65100:1 and target:65100:2

target:65100:1 and target:65100:3

target:65100:1, target:65100:2 and target:65100:3

Configuring labeled eBGP sessions between CSC-CE and CSC-PE routers.

Configuring a policy on each CSC-CE to advertise local PE addresses to the network provider.

Configuring labeled iBGP sessions between PEs residing in different customer carrier sites.

Advertising the received system addresses of remote PEs using either iBGP or IGP/LDP within each customer carrier site.

Show router bgp routes

Show router route-table summary

Show router bgp routes vpn-ipv4 detail

Show router route-table

MP-BGP for exchanging customer routes with other PEs.

A routing protocol for exchanging customer routes with the CE.

A label signaling protocol for defining transport tunnels between the PE and CE.

MPLS for exchanging labels with other provider core devices.

Signaled via MP-BGP and used to identify the egress PE.

Signaled via T-LDP and used to identify the customer VPRN.

Signaled via MP-BGP and used to identify the customer VPRN.

Signaled via RSVP and LDP and used to identify the egress PE.

Signaled via RSVP and LDP and used to identify the customer VPRN.

iBGP

eBGP

MP-iBGP

MP-eBGP

Either a hub and spoke or an extranet VPRN

An extranet VPRN

A hub and spoke VPRN

Either a full mesh or a hub and spoke VPRN

The route update sent from PE1.

The route update sent from PE2.

The route update sent from ASBR1.

The route update sent from ASBR2.

VPN-IPv4 routes are neither held, nor re-advertised, by the ASBRs.

Each ASBR propagates the routes received from its neighbor ASBR as labeled IPv4 routes in its own AS.

ASBRs exchange labeled IPv4 routes for the system addresses of PE routers.

ASBRs exchange customer routes as labeled IPv4 routes.

Two SDPs must be bound to the VPRN service on each PE.

Three SDPs must be bound to the VPRN service on each PE.

Five SDPs must be bound to the VPRN service on each PE.

Twelve SDPs must be bound to the VPRN service on each PE.

This configuration is correct and complete.

This configuration is correct, except that the system interface must be added.

This configuration is correct, except that the interfaces facing the CE routers must be added.

MPLS configuration is not required.

ASBR2 has a total of three BGP sessions established: one with PE2, one with RR2, and one with ASBR1.

RR1 has a total of three BGP sessions established: one with PEL one with RR2, and one with ASBRL

PE2 has a total of two BGP sessions established: one with RR2 and one with ASBR2.

PE1 has a total of two BGP sessions established: one with RR1 and one with PE2.

Traditional BGP loop detection mechanisms are unable to detect a loop in a VPRN scenario.

BGP loops are detected in a VPRN when the customer has separate sites using the same BGP autonomous system number.

The Nokia 7750 SR rejects routes containing AS_PATH loops by default.

When " remove-private " is configured at a PE, all routes received from the associated CE will have private AS numbers removed.

The route learned from an eBGP peer.

The route with the lowest Origin.

The route with the lowest originator ID or BGP Identifier.

The route with the shortest AS path.

PE1 advertises spoke routes to CE1.

The primary VRF on PE1 is used to route data packets from the hub CE to the spoke sites.

The secondary VRF on PE1 contains routes learned from the spoke sites.

Spoke sites do not learn routes from other spoke sites directly.

Option A

Option B

Option C

Option D

The primary VRF on PE1 contains routes learned from spoke sites.

All traffic between spoke sites must pass through CE1.

The secondary VRF on PE1 is used to route data packets from the hub CE to the spoke sites.

PE1 advertises the primary VRF routes to CE1.

CE2 forwards an unlabeled IP packet to PE2 via the VPRN interface.

PE2 pushes one label on the IP packet and label-switches it to ASBR2.

ASBR2 forwards an unlabeled IP packet to ASBR1.

ASBR1 pushes two labels on the IP packet and label-switches the packet to PE1.