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QUESTION 30
Which three functions are performed by the PE router in an MPLS Layer 3 VPN? (Choose three.)
A. exchanges routing updates with the CE router
B. translates the CE routing information into VPNv4 routes
C. exchanges VPNv4 routes with other PE routers over MP-BGP
D. imports and exports RTs that are received from the P routers
E. exchanges RDs with the P routers
F. exchanges VPN labels with the CE routers

Correct Answer: ABC Section: (none) Explanation
Explanation/Reference:
Explanation:
http://www.cisco.com/en/US/docs/routers/crs/software/crs_r4.1/lxvpn/configuration/guide/vc41v3.html

How MPLS L3VPN Works
MPLS VPN functionality is enabled at the edge of an MPLS network. The PE router performs the following tasks:
.
Exchanges routing updates with the CE router

.
Translates the CE routing information into VPN version 4 (VPNv4) and VPN version 6 (VPNv6) routes

.
Exchanges VPNv4 and VPNv6 routes with other PE routers through the Multiprotocol Border Gateway Protocol (MP-BGP)
QUESTION 31
Which BGP extended community is used to control the distribution of VPN routing information and to identify routers that may receive a set of routes that carry the community?
A. SOO
B. RT
C. opaque
D. route origin
E. RD

Correct Answer: B Section: (none) Explanation
Explanation/Reference:
Explanation:
http://blog.initialdraft.com/archives/1537/
Route Target is a 64-bits BGP community used for tagging prefixes. When exporting prefixes from the VRF, we add to the prefixes a Route-Target community, so when the PE in the remote site has to import prefixes into the VRF, it can easily identify which prefixes to import.
QUESTION 32
In which configuration mode is a route distinguisher configured in a Cisco IOS XR router?
A. config-vrf
B. config-vrf-af
C. config-bgp
D. config-bgp-af
E. config-bgp-vrf

Correct Answer: E Section: (none) Explanation
Explanation/Reference:
Explanation: http://www.cisco.com/en/US/docs/ios_xr_sw/iosxr_r3.6/routing/configuration/guide/rc36book.pdf

QUESTION 33
Refer to the exhibit.

Given the output shown, which two statements are true? (Choose two.)
A. The configured remote AS for neighbor 10.1.1.1 is 1234.
B. Both prefixes that are referenced by network commands will be visible with the show bgp command from the information that is shown in the output.
C. The neighbor 10.1.1.1 cannot learn any routes from this router.
D. The router cannot learn any routes for neighbor 10.1.1.1.
E. Routes from the Internet VRF that are injected into BGP through redistribution will be advertised to neighbor 10.1.1.1.

Correct Answer: AC Section: (none) Explanation
Explanation/Reference:
Explanation:
QUESTION 34
Which Layer 2 VPN technology is implemented over an IP core network without the need for MPLS?
A. VPLS
B. VPWS
C. AToM
D. L2TPv3

Correct Answer: D Section: (none) Explanation Explanation/Reference:
Explanation:
http://www.cisco.com/en/US/docs/ios/12_3t/12_3t2/feature/guide/gtl2tpv3.html#wp1040784
The Layer 2 Tunnel Protocol Version 3 feature expands on Cisco support of the Layer 2 Tunnel Protocol Version 3 (L2TPv3). L2TPv3 is an Internet Engineering Task Force (IETF) l2tpext working group draft that provides several enhancements to L2TP for the capability to tunnel any Layer 2 payload over L2TP. Specifically, L2TPv3 defines the L2TP protocol for tunneling Layer 2 payloads over an IP core network using Layer 2 virtual private networks (VPNs). Benefits of this feature include the following:
.
L2TPv3 simplifies deployment of VPNs

.
L2TPv3 does not require Multiprotocol Label Switching

.
L2TPv3 supports Layer 2 tunneling over IP for any payload
QUESTION 35
Which two Layer 2 VPN methods support interworking between customer sites with different Layer 2 encapsulation at each end (for example, Frame Relay to Ethernet interworking)? (Choose two.)
A. AToM
B. VPLS
C. GET VPN
D. L2TPv3

Correct Answer: AD Section: (none) Explanation
Explanation/Reference:
Explanation:
http://www.cisco.com/en/US/docs/ios/12_3t/12_3t2/feature/guide/gtl2tpv3.html#wp1040784
The Layer 2 Tunnel Protocol Version 3 feature expands on Cisco support of the Layer 2 Tunnel Protocol Version 3 (L2TPv3). L2TPv3 is an Internet Engineering Task Force (IETF) l2tpext working group draft that provides several enhancements to L2TP for the capability to tunnel any Layer 2 payload over L2TP. Specifically, L2TPv3 defines the L2TP protocol for tunneling Layer 2 payloads over an IP core network using Layer 2 virtual private networks (VPNs). Benefits of this feature include the following:
.
L2TPv3 simplifies deployment of VPNs

.
L2TPv3 does not require Multiprotocol Label Switching

.
L2TPv3 supports Layer 2 tunneling over IP for any payload
http://www.cisco.com/en/US/products/ps6646/products_ios_protocol_option_home.html
Cisco Any Transport over MPLS (AToM) is a solution for transporting Layer 2 packets over an MPLS backbone. It enables Service Providers to supply connectivity between customer sites with existing data link layer (Layer 2) networks via a single, integrated, packet-based network infrastructure: a Cisco MPLS network. Without separate networks that each have network management environments, Service Providers can deliver Layer 2 connections over an MPLS backbone. Cisco AToM provides a common framework to encapsulate and transport supported Layer 2 traffic types over an MPLS network core. Service Providers can use a single MPLS network infrastructure to offer
connectivity for supported Layer 2 traffic and for IP traffic in Layer 3 VPNs.
QUESTION 36
What are the two AToM interworking modes? (Choose two.)
A. bridged (interworking ethernet)
B. routed (interworking ip)
C. label-switched (interworking mpls)
D. transparent (interworking transparent)

Correct Answer: AB Section: (none) Explanation
Explanation/Reference:
Explanation: http://www.cisco.com/en/US/docs/ios/ios_xe/mpls/configuration/guide/mp_l2vpn_intrntwkg_xe.html
Interworking is a transforming function that is required to interconnect two heterogeneous attachment circuits (ACs). Several types of interworking functions exist. The function that is used would depend on the type of ACs being used, the type of data being carried, and the level of functionality required. The two main Layer 2 Virtual Private Network (L2VPN) interworking functions supported in Cisco IOS XE software are bridged and routed interworking.
Layer 2 (L2) transport over multiprotocol label switching (MPLS) and IP already exists for like-to-like ACs, such as Ethernet-to-Ethernet or Point-to-Point Protocol (PPP)-to-PPP. L2VPN Interworking builds on this functionality by allowing disparate ACs to be connected. An interworking function facilitates the translation
between different L2 encapsulations.
QUESTION 37
When implementing EoMPLS on Cisco IOS XR routers, which command under the l2vpn configuration mode is used to define the pseudowire?
A. pbb
B. xconnect
C. connect
D. bridge
E. bridge-domain

Correct Answer: B Section: (none) Explanation
Explanation/Reference:
Explanation: http://www.cisco.com/en/US/docs/wireless/asr_901/Configuration/Guide/eompls.html

QUESTION 38

When configuring an EoMPLS PW on a Cisco IOS XR router, what are the two supported transport modes? (Choose two.)
A. ethernet (Ethernet port mode)
B. ip (routed mode)
C. vlan (VLAN-tagged mode)
D. transparent (bridged mode)

Correct Answer: AC Section: (none) Explanation
Explanation/Reference:
Explanation: http://www.cisco.com/en/US/docs/ios_xr_sw/iosxr_r3.8/mpls/configuration/guide/gc38v2.html#wp1072883
.
Ethernet Port Mode

.
Ethernet Remote Port Shutdown

.
VLAN Mode

.
Inter-AS Mode

.
QinQ Mode

.
QinAny Mode

.
Mac-in-Mac Protocol (Provide Backbone Bridging)
QUESTION 39
When implementing EoMPLS PWs, which configuration is optional?
A. matching PW ID on both ends
B. Xconnect
C. Cisco Express Forwarding
D. control word

Correct Answer: D Section: (none) Explanation
Explanation/Reference:
Explanation:

QUESTION 40
Which method is used to provide inter-AS AToM services?
A. back-to-back VRF
B. targeted LDP
C. pseudowire stitching
D. AToM interworking
E. Cisco MPLS TE tunnels
F. autodiscovery
Correct Answer: C Section: (none) Explanation

Explanation/Reference:
Explanation:
http://www.cisco.com/en/US/docs/optical/cpt/r9_3/configuration/guide/ cpt93_configuration_chapter_0111.html
QUESTION 41
When troubleshooting EoMPLS configuration problems, which three parameters must match between the two ends of the pseudowire configurations? (Choose three.)
A. control word usage
B. MTU size
C. pseudowire ID
D. Xconnect group name
E. EFP subinterface number

Correct Answer: ABC Section: (none) Explanation
Explanation/Reference:
Explanation:

Provisioning an AToM Static Pseudowire
In this configuration task, you use options in the xconnect Ethernet interface configuration command to specify a static connection, and mpls commands in xconnect mode to statically set the following pseudowire parameters:
.
Set the local and remote pseudowire labels

.
Enable or disable sending the MPLS control word
Haven’t been able to find where MTU Must match
QUESTION 42
Which Layer 2 protocol parameters can be carried inside the control word when implementing AToM service?
A. PW ID
B. Frame Relay FECN, BECN, and DE bits
C. encapsulation type
D. VC type

Correct Answer: B Section: (none) Explanation
Explanation/Reference:
Explanation: http://www.cisco.com/en/US/products/ps6603/products_qanda_item09186a008009d4e3.shtml#wp39173
Q. How does Frame Relay over MPLS work?
A. Traffic is encapsulated in MPLS packets and forwarded across the MPLS network. When encapsulating Frame Relay over MPLS, the Frame Relay header and the frame check sequence (FCS) are stripped from the packet. The bits for Backward Explicit Congestion Notification (BECN), Forward Explicit Congestion Notification (FECN), Discard Eligibility (DE) and Command/Response (C/R) are carried across the MPLS
network in the “Control Word” header.
QUESTION 43
When implementing VPLS on Cisco routers, which data structure resembles a virtual switch and is used for learning the MAC addresses?
A. VRF
B. VFI
C. SVI
D. BVI

Correct Answer: B Section: (none) Explanation
Explanation/Reference:
Explanation:

QUESTION 44
In hierarchical VPLS implementations, which two access architectures can be used between the UPE and NPE? (Choose two.)
A. EoMPLS
B. MP-BGP
C. Frame Relay
D. 802.1ad

Correct Answer: AD Section: (none) Explanation
Explanation/Reference:
Explanation:
http://www.cisco.com/en/US/docs/switches/metro/me3600x_3800x/software/release/12.2_52_ey/ configuration/guide/swmpls.html#wp1244272
H-VPLS uses spoke connections, usually between Layer 2 switches acting as the CE and PE devices at the service provider’s point-of presence (POP). The spoke connections can be either an IEEE 802.1Q tagged connection or an MPLS LSP.
QUESTION 45
Which two methods can be used for VPLS PW signaling? (Choose two.)
A. static
B. BGP
C. IGP
D. LDP
E. RSVP

Correct Answer: BD Section: (none) Explanation
Explanation/Reference:
Explanation:

QUESTION 46
When implementing nonhierarchical VPLS with eight PE routers, how many total PWs will be required between the PE routers?
A. 8
B. 16
C. 28
D. 32
E. 64

Correct Answer: C Section: (none) Explanation
Explanation/Reference:
Explanation:
8 * (8-1) /2
QUESTION 47
VPWS/EoMPLS offers which type of Ethernet services as defined by the MEF?
A. E-Tree
B. E-LAN
C. E-Line
D. E-Interworking

Correct Answer: C Section: (none) Explanation
Explanation/Reference:
Explanation:
. E-Line is based on a point-to-point Ethernet Virtual Connection. Two E-Line services are defined:

Ethernet Private Line (EPL): A very simple and basic point-to-point service characterized by low frame delay, frame delay variation, and frame loss ratio. No service multiplexing is allowed, and other than a committed information rate (CIR) no class of service (CoS) (Bandwidth Profiling) is allowed.


Ethernet Virtual Private Line (EVPL): A point-to-point service wherein service multiplexing (more than one Ethernet Virtual Connection) is allowed. The individual Ethernet Virtual Circuits can be defined with a rich set of Bandwidth Profiles and Layer 2 Control Protocol Processing methods as defined by the Metro Ethernet Forum.
QUESTION 48
When using the Cisco EVC software infrastructure, a double-tagged frame with a customer VLAN of 10 and a service provider VLAN of 150 will be best matched by which encapsulation configuration?
A. encapsulation dot1q 10 second-dot1q any
B. encapsulation dot1q 10 second-dot1q 150
C. encapsulation dot1q 10 second-dot1q 50-200
D. encapsulation dot1q 10
E. encapsulation dot1q 150

Correct Answer: B Section: (none) Explanation
Explanation/Reference:
Explanation:

QUESTION 49
When implementing H-VPLS with QinQ access on Cisco Metro Ethernet switches, which two commands enable the QinQ tagging? (Choose two.)
A. encapsulation dot1q {customer-vlan} second-tag {sp-vlan}
B. encapsulation dot1q {sp-vlan} second-tag {customer-vlan}
C. switchport mode dot1q-tunnel
D. switchport mode trunk
E. switchport access vlan {sp-vlan} F. switchport access vlan {customer-vlan}

Correct Answer: CE Section: (none) Explanation
Explanation/Reference:
Explanation:
QUESTION 50
Implementing H-VPLS instead of VPLS reduces which requirement?
A. having a full mesh of PWs between all the PE routers in the service provider MPLS core
B. having a full mesh of PWs between all the UPE routers
C. having to implement QinQ tagging between the UPE and the NPE
D. having to implement MPLS LDP between the UPE and the NPE
E. the overhead of using BGP or LDP autodiscovery

Correct Answer: A Section: (none) Explanation
Explanation/Reference:
Explanation:

QUESTION 51
When implementing VPLS on Cisco IOS XR routers, the customer-facing subinterfaces on the PE routers are assigned to which Cisco EVC component?
A. bridge group
B. bridge domain
C. VFI
D. Layer 2 transport
E. BVI

Correct Answer: B Section: (none) Explanation
Explanation/Reference:
Explanation:

QUESTION 52
What is an advantage of using the Cisco EVC infrastructure to implement carrier-class Ethernet services that are not available on non-EVC-capable platforms?
A. PW redundancy
B. interworking support
C. PW stitching support
D. flexible frame-matching support and VLAN tag manipulation
E. local cross-connect support

Correct Answer: D Section: (none) Explanation
Explanation/Reference:
Explanation:
http://www.cisco.com/web/YU/events/expo_08/pdfs/Carrier_Ethernet_Marek_Moskal.pdf

QUESTION 53
When implementing a Layer 2 transport subinterface on a Cisco IOS XR router, which encapsulation option is used to match any packets that are not matched by any other service instances?
A. default
B. untagged
C. any
D. tag

Correct Answer: A Section: (none) Explanation
Explanation/Reference:
Explanation:

QUESTION 54
When configuring VPLS on the Cisco ASR 9000, which three configurations are required under the l2vpn configuration mode? (Choose three.)
A. bridge-group
B. bridge-domain
C. xconnect
D. vfi
E. encapsulation

Correct Answer: ABD Section: (none) Explanation
Explanation/Reference:
Explanation:
QUESTION 55
Which option is the correct command to define an interface as Layer 2 on the Cisco ASR 9000?
A. RP/0/RSP0/CPU0:R1(config)#int gigabitEthernet 0/6/0/0 l2transport
B. RP/0/RSP0/CPU0:R1(config)#int gigabitEthernet 0/6/0/0 layer2
C. RP/0/RSP0/CPU0:R1(config)#int gigabitEthernet 0/6/0/0 switchport
D. RP/0/RSP0/CPU0:R1(config)#int gigabitEthernet 0/6/0/0 xconnect

Correct Answer: A Section: (none) Explanation
Explanation/Reference:
Explanation:

QUESTION 56
When implementing MPLS Layer 3 VPN services, which CE-PE routing method does not require the use of the redistribute command to enable the customer routes to be advertised through the MPLS cloud between the customer sites?
A. EIGRP
B. OSPF
C. IS-IS
D. BGP
E. static routing
F. OSPF or IS-IS

Correct Answer: D Section: (none) Explanation
Explanation/Reference:
Explanation:
QUESTION 57
In MPLS Layer 3 VPN implementations, what is used at the PEs to transform the customer IPv4 prefixes into a unique 96-bit prefix?
A.RT
B. RD
C. VC ID
D. PW ID
E. AS number

Correct Answer: B Section: (none) Explanation
Explanation/Reference:
Explanation:
http://blog.initialdraft.com/archives/1537/
QUESTION 58
With Layer 3 MPLS VPN implementations on Cisco IOS XR PE routers, an interface is assigned to a VRF using the vrf command in which configuration mode?
A. RP/0/RP0/CPU0:PE(config-vrf)#
B. RP/0/RP0/CPU0:PE(config-if)#
C. RP/0/RP0/CPU0:PE(config-bgp)#
D. RP/0/RP0/CPU0:PE(config-bgp-af)#

Correct Answer: B Section: (none) Explanation
Explanation/Reference:
Explanation:

QUESTION 59
Refer to the partial Cisco IOS XR PE router configuration exhibit for supporting a Layer 3 MPLS VPN customer using EIGRP AS 20 as the CE-to-PE routing protocol.

The MPLS VPN customer is having problems receiving the EIGRP routes on the different customer site CE routers. What is wrong with this configuration that is causing the problem?
A. The router eigrp command is referencing the wrong AS number.
B. The redistribute eigrp command is missing the metric transparent option.
C. The redistribute eigrp command is referencing the wrong AS number.
D. The redistribute bgp command is missing the subnets option.
E. The redistribute eigrp command is missing the subnets option.

Correct Answer: C Section: (none) Explanation
Explanation/Reference:
Explanation:
QUESTION 60
In which Cisco IOS XR configuration mode is the redistribute static command applied to enable the redistribution of static VRF routes between the PE routers?
A. RP/0/RP0/CPU0:PE(config-router)#
B. RP/0/RP0/CPU0:PE(config-bgp)#
C. RP/0/RP0/CPU0:PE(config-bgp-vrf)#
D. RP/0/RP0/CPU0:PE(config-bgp-vrf-af)#

Correct Answer: D Section: (none) Explanation
Explanation/Reference:
Explanation:
http://www.cisco.com/en/US/docs/routers/asr9000/software/routing/configuration/guide/ rcasr9kstat.html#wp1041359

QUESTION 61
What is required on a Cisco IOS XR router to assign an interface to a VRF?
A. Assign the VRF to the interface, and then re-enable Cisco Express Forwarding on the interface.
B. Assign the VRF to the interface, and then reset the CE-to-PE routing protocol process.
C. Shut the interface, assign the VRF to the interface, and then no shut the interface.
D. Remove the IP address configuration on the interface, assign the VRF to the interface, and then reconfigure the IP address on the interface.

Correct Answer: D Section: (none) Explanation
Explanation/Reference:
Explanation:
http://www.cisco.com/en/US/docs/ios_xr_sw/iosxr_r3.5/mpls/configuration/guide/gc35v3.html#wp1080845

QUESTION 62
When implementing VPLS on Cisco IOS XR routers, the VPLS PW neighbors can be statically defined under which configuration mode?
A. bridge group
B. bridge-domain
C. vfi
D. mpls ldp
E. l2transport

Correct Answer: C Section: (none) Explanation
Explanation/Reference:
Explanation:

QUESTION 63
On Cisco IOS XR platforms using the EVC infrastructure, which command is used to enable a Layer 2 VPN subinterface?
A. interface gi0/0/0/0.10 switchport access vlan 10
B. interface gi0/0/0/0.10 switchport mode tunnel dot1q-tunnel
C. interface gi0/0/0/0.10 switchport mode trunk
D. interface gi0/0/0/0.10 bridge-group 10
E. interface gi0/0/0/0.10 l2transport

Correct Answer: E Section: (none) Explanation
Explanation/Reference:
Explanation:

QUESTION 64
In Layer 3 MPLS VPN implementations, which protocol is used to carry the VPNv4 routes from PE to PE?
A. RSVP
B. IGP
C. MP-BGP
D. LDP

Correct Answer: C Section: (none) Explanation
Explanation/Reference:
Explanation:
QUESTION 65
What happens if the destination MAC address is not present in the table for the packets that are received on one of the ACs in VPLS?
A. Packets are switched only to the PW.
B. Packets are flooded only to the other local ACs.
C. Packets are flooded on all other ACs and on all PWs that are associated with the bridge domain.
D. Packets are dropped.

Correct Answer: C Section: (none) Explanation
Explanation/Reference:
Explanation:
QUESTION 66

On PE7, which interface connects to the CE7 and what is the name of the VRF that interface is assoicated to? (Choose two.)
A. Gi0/0/0/0
B. Gi0/0/0/1
C. Gi0/0/0/2
D. Customer_1
E. Customer_A
F. Customer_CE7

Correct Answer: AD Section: (none) Explanation
Explanation/Reference:
Explanation: # show ip vrf interfaces
QUESTION 67

What type of routing is used between CE7 and PE7?
A. OSPF
B. BGP
C. is-is
D. RIPv2
E. Static routing

Correct Answer: E Section: (none) Explanation
Explanation/Reference:
Explanation: # show ip route
QUESTION 68

On PE7, how many multiprotocol IBGP routes are learned from PE8 and what is the next-hop IP address? (Choose two.)
A. 1
B. 2
C. 3
D. 10.8.1.1
E. 172.16.8.1
F. 192.168.108.81

Correct Answer: BD Section: (none) Explanation
Explanation/Reference:
Explanation: show ip bgp vpnv4 all — i tag field is the answer
QUESTION 69

On PE7, which three statements are correct regarding the MPLS VPN configurations used to supportthe connectivity between the CE7 and CE8 sites?
(Choose three.)
A. The RD is 1:1
B. The import and export RTs are 1:1
C. Interface GiO/0/0/0 is associated to the “default” VRF
D. The network that connects PE7to CE7 is redistributed into multiprotocol IBGP
E. The multiprotocol IBGP routes learned have a BGP origin code of”i”

Correct Answer: ABD Section: (none) Explanation
Explanation/Reference:
Explanation: # show ip route show ip vrf show ip vrf detail
QUESTION 70
On PE7, what is the pseudowire ID that connects to the 10.8.1.1 neighbor?
A. 70
B. 80
C. 123
D. 0x840001
E. 0x4000080

Correct Answer: C Section: (none) Explanation
Explanation/Reference:
Explanation: # show vfi
QUESTION 71
Which statement is correct regarding the pseudowire on connects PE7 to the 10.8.1.1 neighbor?
A. The control word is enabled on both ends of the pseudowire
B. The MTU size is 1500 bytes on both ends of the pseudowire
C. Pseudowire backup is enabled
D. The pseudowire is in the down state

Correct Answer: B Section: (none) Explanation
Explanation/Reference:
Explanation: show xconnect all show ip interface brief show mpls l2transport vc show cable l2-vpn xconnect mpls-vc-map
QUESTION 72
On PE7, which encapsulation method is used on the pseudowire that connects to the 10.8.1.1 neighbor?
A. MPLS
B. L2TPv3
C. IP
D. LDP
E. Ethernet

Correct Answer: A Section: (none) Explanation
Explanation/Reference:
Explanation: show xconnect all check value is mpls or l2tp or Ethernet etc in segment field
QUESTION 73
On PE7, what is the PWtype on the p2p ac-pw named “testpw”?
A. MPLS
B. L2TPv3
C. PPP
D. LDP
E. Ethernet

Correct Answer: E Section: (none) Explanation
Explanation/Reference:
Explanation: show mpls l2transport vc testpw detail
QUESTION 74
Select and Place:

Correct Answer: Section: (none) Explanation
Explanation/Reference:
Explanation:
802.1ad and 802.1ah —- IEEE VPWS and VPLS —- IETF E-Line , E-LAN and E-Tree — MEF
http://www.cisco.com/application/pdf/en/us/guest/tech/tk891/c1482/cdccont_0900aecd80162184.pdf

QUESTION 75 Select and Place: Correct Answer:

Section: (none) Explanation
Explanation/Reference:
Explanation:
802.1ah PBB 802.1ad QinQ 802.1ag Connectivity fault management

Benefits of IEEE 802.1ah standard
The benefits of IEEE 802.1ah provider backbone bridges are as follows:
.
Increased service instance scalability

.
MAC address scalability IEEE 802.1ah Standard for Provider Backbone Bridging Overview
The IEEE 802.1ah Provider Backbone Bridge feature encapsulates or decapsulates end user traffic on a Backbone Edge Bridge (BEB) at the edge of the Provider Backbone Bridged Network (PBBN). A Backbone Core Bridge (BCB) based network provides internal transport of the IEEE 802.1ah encapsulated frames within the PBBN.
Overview of OAM
The advent of Ethernet as a metropolitan and wide-area networking technology has accelerated the need for a new set of OAM protocols. Service provider networks are large and complex with a wide user base, and they often involve different operators that must work together to provide end-to-end services to enterprise customers. While enterprise end-customer demands continue to increase, so do the requirements for service provider Ethernet networks, particularly in the areas of availability and mean time to repair (MTTR). Ethernet OAM addresses these challenges and more, thereby directly impacting the competitiveness of the service provider. Ethernet has been used as a LAN technology for many years, and enterprises have managed these networks effectively, primarily with the use of Internet protocols such as Simple Network Management Protocol (SNMP), ICMP Echo (or IP Ping), IP Traceroute, and Cisco Unidirectional Link Detection Protocol (UDLD) and Layer 2 Traceroute (supported in Cisco Catalyst. OS and some Cisco IOS. Software-based platforms). In addition to these troubleshooting protocols, Cisco provides a wealth of other configuration, fault, network management, and performance management tools. Cisco also supports MPLS OAM capabilities such as Virtual Circuit Connectivity Verification (VCCV) and
Label Switched Path (LSP) ping on the Carrier Ethernet platforms. To complement these OAM capabilities
and to ensure that Ethernet can deliver the required customer service-level agreements (SLAs), Cisco has
developed comprehensive Ethernet and IP SLA agents, along with an embedded event manager (EEM),
and IPTV video quality tools for automated measurement and troubleshooting of Carrier Ethernet
deployments.
Ethernet OAM addresses the following challenges:

.
The existing protocols mentioned earlier will not work unless the Ethernet layer is operating properly, making Ethernet OAM a prerequisite.

.
Many service providers do not want to overlay an IP infrastructure simply for management and troubleshooting of Layer 2 Ethernet services.

.
The current management protocols lack the per-customer or per-service granularity that is required to manage the individual Layer 2 Ethernet services provided to enterprises.

.
The existing protocols do not assist with provisioning of Ethernet services, which is particularly difficult when the service provider and end customer must coordinate the configurations on their respective Ethernet equipment.
Ethernet OAM is a broad topic, but this paper will focus on three main areas of Ethernet OAM that are most in need by service providers and are rapidly evolving in the standards bodies: Service Layer OAM (IEEE 802.1ag Connectivity Fault Management), Link Layer OAM (IEEE 802.3ah OAM), and Ethernet Local Management Interface (MEF-16 E-LMI). Each of these different OAM protocols has unique objectives and is complementary to the others
IEEE 802.1ad[note 1] is an Ethernet networking standard informally known as IEEE 802.1QinQ and is an amendment to IEEE standard IEEE 802.1Q-1998. The technique is also known as provider bridging, Stacked VLANs or simply QinQ or Q-in-Q. The original 802.1Q specification allows a single VLAN header to be inserted into an Ethernet frame. QinQ allows multiple VLAN headers to be inserted into a single frame, an essential capability for implementing Metro Ethernet network topologies. Just as QinQ extends 802.1Q, QinQ itself is extended by other Metro Ethernet protocols.[specify] In a multiple VLAN header context, out of convenience the term “VLAN tag” or just “tag” for short is often used in place of “802.1Q VLAN header”. QinQ allows multiple VLAN tags in an Ethernet frame; together these tags constitute a tag stack. When used in the context of an Ethernet frame, a QinQ frame is a frame that has 2 VLAN 802.1Q headers (double-tagged). There is a mild confusion regarding the naming because the 802.1ad standard was grown out of the 802.1QinQ protocol (which was developed based the trademarked method 802.1Q, with capital “Q” as a distinction instead of the 802.1q as the standardised protocol) which originally used 0x9100 as ethernet type instead of 0x88a8. While the network industry usually mix the naming the proper, standardised name is 802.1ad which sometimes gets appended by the other alternative names mentioned above; the plain “802.1QinQ” name usually refers to the old standard which is now considered obsolete
QUESTION 76
Select and Place:

Correct Answer: Section: (none) Explanation

Explanation/Reference:
Explanation:
Point-Point — E-Line Multipoint ?o-Multipoint ?E-Lan Rooted multipoint — E-Tree
Business subscribers are an important segment of many service providers’ customer base. The main business services that must be provided by the network today are:
. MPLS VPN

. Carrier Ethernet connectivity

. Managed services

Carrier Ethernet connectivity services have been defined by the Metro Ethernet Forum (MEF) to include E-Line, E-LAN, and E-Tree service types, which are defined as follows:

. E-Line is based on a point-to-point Ethernet Virtual Connection. Two E-Line services are defined:
每 Ethernet Private Line (EPL): A very simple and basic point-to-point service characterized by low frame delay, frame delay variation, and frame loss ratio. No service multiplexing is allowed, and other than a committed information rate (CIR) no class of service (CoS) (Bandwidth Profiling) is allowed.

每 Ethernet Virtual Private Line (EVPL): A point-to-point service wherein service multiplexing (more than one Ethernet Virtual Connection) is allowed. The individual Ethernet Virtual Circuits can be defined with a rich set of Bandwidth Profiles and Layer 2 Control Protocol Processing methods as defined by the Metro Ethernet Forum.
. E-LAN is based on a multipoint-to-multipoint Ethernet Virtual Connection. Service multiplexing (more than one Ethernet Virtual Circuit at the same UNI) is permitted, as is the rich set of performance assurances defined by the MEF such as CIR with an associated Committed Burst Size (CBS) and Excess Information Rate (EIR).

. E-Tree is a point-to-multipoint ELAN service in which the spoke “leaves” can communicate with the hub or “root” location but not with each other. Typical application for E-Tree is in franchise operations.

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