4A0-106 Sample Questions Answers

Resources consumed at the sender and receiver PEs can be reduced by using BGP ORF.

BGP ORF allows a receiving PE to filter out unnecessary inbound routes.

A PE indicates its ORF capabilities to its neighbor PE in a BGP Open message.

BGP ORF is most effective when a large number of routes is being exchanged between two peers, and most routes are filtered out on arrival.

The route with the shortest AS path.

The route with the lowest route or tunnel table cost to the NEXT_HOP.

The route with the highest local preference.

The route with the lowest originator ID or BGP identifier.

The VRF 10 on CSC-PE1 includes PE1 and PE2's system addresses.

The global routing table of PE1 includes PE2's system address.

The VRF 10 on CSC-PE2 includes CEI'S address.

The global routing table of PE2 includes CE1's address.

show service id base

show router Idp bindings

show service id sdp detail

show service id vc-mtu

This command is required on all PE routers to distribute labeled IPv4 routes directly to PEs in remote AS.

This command is required on the ASBRs to exchange labeled IPv4 routes between the ASs.

This command is required on the route reflectors to exchange customer routes between ASs as labeled IPv4 routes.

This command is required on all PE routers to distribute labeled IPv4 routes to connected CEs.

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

Creating an export policy on CSC-CE1 and CSC-CE2 to advertise local PE addresses to the network provider.

Configuring eBGP between CSC-CE and CSC-PE routers; setting the address family to IPv4; and enabling the advertisement of labels for IPv4 routes.

Configuring iBGP between PE and CSC-CE within each customer carrier site; setting the address family to IPv4; and enabling the advertisement of labels for IPv4 routes.

Configuring MP-iBGP between PE1 and PE2; setting the address family to IPv4; and enabling the advertisement of labels for IPv4 routes.

"Spoke.Sites" and "Hub_Site"

"Hub_Site"

"Spoke_Sites"

No communities should be imported

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

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.

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.

64496 64497

64496

64497

64497 64497

PE1 pushes an LDP transport label.

CSC-PE1 pops the BGP label and pushes two labels: a VPN label and an MPLS transport label.

CSC-PE2 pops the MPLS transport label and pushes a BGP label.

CSC-CE2 pops the BGP label and pushes an LDP transport label.

BGP sessions between RR1 and PE routers support only the IPv4 address family.

BGP sessions between RR2 and PE routers support only the VPN-IPv4 address family.

RR2 establishes BGP sessions with PEL PE2 and PE3.

RR1 establishes BGP sessions only with PE1 and PE2.

The VPRN ID must match the value 101 used in the vrf-target command.

The VPRN ID must match the value 101 used in the route-distinguisher command.

The router-id command should not be used in this context.

The “no shutdown” command must be configured for the VPRN to be operationally UP.

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.

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.

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

The Route Target is added to an IPv4 route to create the VPN-IPv4 route.

The Route Target is an extended community string that identifies VPN membership.

A route can have only one Route Target.

The Route Target is a 64-bit value added to customer prefixes to make them unique.

Option A

Option B

Option C

Option D

MP-iBGP sessions must be configured between the PE routers in each AS.

LDP must be configured in each AS.

MP-eBGP sessions must be configured between the ASBRs.

The ASBRs must be configured with "enable-inter-as-vpn".

Each PE must implement a policy to apply a unique SoO attribute to the set of routes received from each customer site.

A different BGP extended community is used on each PE that connects to a single site.

An import policy on the PE rejects a route if the attached SoO matches the configured value.

Import and export policies are applied on the PEs under the global BGP context.

PE1 pushes two labels on the IP packet and forwards it to ASBR1.

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

ASBR2 forwards the IP packet with two labels to PE2.

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

PE1 and PE2 advertise the same VPN route to the route reflector.

The route reflector receives two routes for prefix 10.1.1.0/24; one from PE1 and one from PE2.

The route reflector reflects two routes for prefix 10.1.1.0/24.

PE3 receives two routes and is able to load balance traffic across PE1 and PE2.

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.

Red VRF imports only "Internet"

Internet VRF imports only "Red-Only"

Red VRF imports "Internet" and "Red-Only"

Internet VRF imports only "Red-Only"

Red VRF imports only "Red-Only"

Internet VRF imports "Red-Only" and "Internet"

Red VRF imports "Internet" and "Red-Only"

Internet VRF imports only "Internet"

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

CSC-CE1 pops the LDP label and swaps the BGP label.

CSC-PE1 pops the BGP label, swaps the VPN label, and pushes an LDP transport label.

CSC-PE2 pops the LDP and VPN labels and pushes a BGP label.

An MP-eBGP session between route reflectors in different autonomous systems to exchange IPv4 routes.

An MP-eBGP session between ASBRs to exchange labeled IPv4 routes.

An eBGP session between ASBRs to exchange IPv4 routes.

An MP-eBGP session between ASBRs to exchange VPN-IPv4 routes.

64496 64512

64512

64496

64512 64496

Show router bgp routes

Show router bgp routes address-family vpn-ipv4

Show router bgp routes

Show router bgp routes

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

Reduced number of VPN tunnels that need to be managed.

Optimal routing between all sites.

Limited configuration required on the hub PE device.

Site to site redundancy support.

True

False

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

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

By using the MED attribute to carry the OSPF metric.

By defining Extended Communities for use as the Route Target

By using the Cluster List attribute to carry the network prefix

By defining support for the VPN-IPv4 address family

By adding an additional field to the BGP Update to carry the VPRN label

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.

Identify the customer network on the egress PE

Establish the LSPs between PE devices

Identify the egress PE in the MPLS domain

Identify the customer network on the ingress PE

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

0

5

10

15

45

The policy should be applied as an import policy on the PE connected to the main site of Customer 1.

The policy should be applied as an import policy on all the PEs connected to the sites of Customer 1.

The policy should be applied as an export policy on the PE connected to the main site of Customer 1.

The policy should be applied as an export policy on all the PEs connected to the sites of Customer 1.

An MP-BGP update carries an MPLS label that is used as the service label for a VPRN.

There can be multiple Route Targets per route in an MP-BGP update.

There can only be one Route Distinguisher per route in an MP-BGP update.

On a specific PE, the MP-BGP updates for prefixes from a single VPRN carry different labels.

Traditional BGP attributes and MP-BGP attributes are present in an MP-BGP update.

True

False

The Nokia 7750 SR allows the setting of the maximum number of routes that can be accepted in a VRF for a VPRN service.

The "maximum-routes" command is used to specify the maximum number of remote routes that can be held within a VRF for a VPRN service.

When the "maximum-routes" command is used with the "log-only" parameter, new routes are still learned.

Once the "threshold" value is reached, no new routes are added to the VRF.

Any CE device

Any PE device

Any P device

Any router in the service provider core

Any customer router

Global, router

Router, router

Service, router

Router, service

Service, service

Router, global

These routes will not appear on CE-B

Type 1 LSAs

Type 3 LSAs

Type 5 LSAs

Type 7 LSAs

VPRN

BGP/MPLS VPN

VLL

VPLS

IP-VPN

ePipe

The ASBRs use MP-eBGP to peer with each other and exchange IPv4 routes between autonomous systems.

The ASBRs use MP-iBGP to peer with PE routers in their autonomous system and exchange VPN-IPv4 routes.

The ASBRs maintain a mapping of labels for IPv4 routes exchanged between autonomous systems.

The ASBRs require per-VPRN configuration.

OSPF

ISIS

MP-BGP

BGP

Targeted LDP

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.

PE1

RR1

ASBR1

ASBR2

Show service 3

Show service id 3

Show service 3 base

Show service id 3 base

Show service 3 detail

Show service id 3 detail

ASBR1# show router 10 bgp routes vpn-ipv4

ASBR1# show router bgp routes

ASBR1# show router bgp routes vpn-ipv4

ASBR1# show router route-table

It is an 8 byte value containing 3 fields

The Route Distinguisher must have the same value as the Route Target.

The Administrator field contains either an AS number or an IP number

To ensure uniqueness, Route Distinguishers are assigned by the IANA.

The Route Distinguisher is not used if the customer addresses do not overlap

The Assigned Number field must contain a public IP address

oam vprn-ping source destination

oam vprn-ping source destination

vprn-ping router

Ping source

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

Router R1

Router R2

Routers R1 and R2

Router R3

Router R4

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.

0 BGP and 2 MP-BGP sessions

2 BGP and 0 MP-BGP sessions

2 BGP and 1 MP-BGP sessions

2 BGP and 2 MP-BGP sessions

1 BGP and 2 MP-BGP sessions

Participate in service provider core routing

P devices are not required to be MPLS enabled. MPLS is only required on the PE devices

Run a common routing protocol with the CE router

Must support MP-BGP

Do not have any connections to the CE

Must be aware of the VPRNs