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WorksheetsCAMS Carrier Network 2
Total questions: 51
Worksheet time: 30mins
On Cisco routers, which three methods can be used to map traffic into the MPLS traffic engineering tunnel? (Choose three.)
on-demand routing
static routing
optimized edge routing
policy-based routing
autoroute
You are tasked to enable LDP on many of the interfaces on the Cisco CRS-3 router, and because there are many interfaces that need to have LDP enabled, you mistakenly did not enable LDP on all the required interfaces. To prevent this issue from happening again in the future, what could you do the next time you need to enable LDP on many interfaces?
use the mpls ldp auto-config command under the IGP routing process
use the mpls ldp sync command under the IGP routing process
use the interface all command under the MPLS LDP process
use the discovery command under the MPLS LDP process
On a Cisco router, when will the router actually reserve the bandwidth for the MPLS traffic engineering tunnel?
during the autoroute process
during constraint-based routing calculations
on the receipt of the RSVP Path message
on the receipt of the RSVP Resv message
On the Cisco ASR9K router, when using the bandwidth command to specify the minimum guaranteed bandwidth to be allocated for a specific class of traffic, what will be used as the queuing algorithm?
custom queuing
CBWFQ
WFQ
FIFO
priority queuing
Which of the following three statements are correct regarding IPv6 QoS? (Choose three.)
The traffic class field in the IPv6 header can be used to set specific precedence or DSCP values.
A 20-bit flow label field enables per-flow processing.
DS-TE is not supported by IPv6.
Per-hop behavior in IPv6 networks is based on EXP bits.
IPv6 QoS features are configured using the modular QoS CLI on Cisco routers.
When implementing Cisco MPLS TE, the constrained-based path calculations will use which value as the TE cost of each link within the MPLS domain?
By default, it will use the IGP metric, or each link can be assigned a specific value using the admin-weight command.
.It can only use the IGP metric as the TE cost.
It will use the interface bandwidth as the TE cost.
Each link must be assigned a TE cost using the metric command.
Which three statements are correct regarding a Cisco MPLS TE? (Choose three.)
A Cisco MPLS TE tunnel maps onto an LSP path.
Tunnels are bidrectional by default.
Packets that are mapped into a Cisco MPLS TE tunnel will have two labels, with the top label indicating what the tail-end router should do with the packet.
A tunnel that is created with a priority of 0 can pre-empt an existing tunnel with a priority of 7.
CBR takes into account link resource and traffic tunnel attributes.
When using the tunnel mpls traffic-eng path-option 1 explicit name testcommand in Cisco MPLS TE tunnel configurations, the test explicit-path configuration will consist of a list of which values?
tunnel endpoint
resource class affinity
MPLS label
IP address
Which three network services can be implemented using MPLS within the service provider IP NGN core?
(Choose three.)
Layer 2 VPNs
Layer 3 VPNs
traffic engineering
IntServ traffic engineering tunnels
encrypted LSPs
When configuring class-based WRED on Cisco routers, which WRED parameter is not user configurable on a Cisco IOS XR but is user configurable on a Cisco IOS and IOS XE?
the ingress or egress direction where the class-based WRED policy will be applied
the maximum threshold
the minimum threshold
the mark probability denominator
On Cisco routers, which QoS marker is only locally significant?
DSCP
MPLS EXP
IP precedence
QoS group
discard eligible (DE)
What is the term that is used for the label that an LSR assigns and distributes to other LSRs in MPLS?
Local
Remote
Explicit
Explicit Null
Aggregate
On Cisco routers, how is hierarchical QoS implemented?
Within the parent policy, reference another child policy using the policy-map command.
Within the child policy, reference another parent policy using the policy-map command.
Use the policy-map command within a service-policy to implement nested policy-maps.
Within the parent policy-map, reference another child policy-map using the service-policy command.
Which two features are used to provide Cisco MPLS TE node and link protection? (Choose two.)
autoroute
fast reroute
backup tunnels
BFD
Within the service provider core network, which two QoS mechanisms are typically deployed on the P routers? (Choose two.)
LLQ
traffic policing and remarking
WRED
traffic shaping
traffic classification and markings
The Cisco IOS and IOS XE qos pre-classify command allows which kind of packet classification on IP packets that are encapsulated with GRE and IPsec?
allows for packets to be classified based on the ToS byte values before packet encryption.
allows for packets to be classified based on the ToS byte values after packet encryption
allows for packets to be classified based on the packet payload before packet encryption
allows for packets to be classified based on the packet payload after packet encryption
allows for packets to be classified based on the packet header parameters other than the ToS byte values after packet encryption
Which field in the MPLS shim header is used to support different QoS markings?
IP precedence
DSCP
EXP
ToS
S
F. Label
Which three mechanisms are used to implement MPLS TE? (Choose three.)
tunnel interface
CSPF
RSVP
LDP
MP-BGP
Which three mechanisms are used to implement MPLS TE? (Choose three.)
tunnel interface
CSPF
RSVP
LDP
Cisco MPLS TE path setup can be affected by which three tunnel attributes? (Choose three.)
bandwidth
delay
MTU
priority
affinity
Which statement is correct regarding the default MPLS TTL behavior?
When an ingress edge LSR receives an IP packet, it will decrement the IP TTL field by 1; then it will set the MPLS Label TTL field to 255.
When an ingress edge LSR receives an IP packet, it will decrement the IP TTL field by 1; then it will copy the decremented IP TTL field into the MPLS Label TTL field.
When an ingress edge LSR receives an IP packet, it will decrement the IP TTL field by 1; then it will copy the decremented IP TTL field into the MPLS Label TTL field.
When an ingress edge LSR receives an IP packet, it will copy the IP TTL field into the MPLS Label TTL field first; then it will only decrement the MPLS Label TTL field by 1.
When an ingress edge LSR receives an IP packet, it will copy the IP TTL field into the MPLS Label TTL field first; then it will only decrement the IP TTL field by 1.
On the Cisco IOS XR, which MQC configuration is different than on the Cisco IOS and IOS XE?
On the Cisco IOS XR, WRED can only be applied in the output direction.
On the Cisco IOS XR, marking can only be applied in the input direction.
On the Cisco IOS XR, LLQ can be applied in the input or output direction.
On the Cisco IOS XR, LLQ can use up to four priority queues: level 1, level 2, level 3, and level 4.
What are the four fields inside the MPLS shim header? (Choose four.)
EXP
TTL
Version
S
Label
With unmanaged CE routers, at which point in the service provider network is the QoS trust boundary, and what is required at the trust boundary?
between the CE and PE router and mapping of the customer traffic classes into the service provider traffic classes at the PE router ingress
between the CE and PE router and trusting the QoS markings from the CE router and applying the required QoS mechanisms based on the customer QoS markings
between the PE and the P router and mapping of the customer traffic classes into the service provider traffic classes at the P router ingress
between the PE and P router and trusting the QoS markings from the CE router and applying the required QoS mechanisms based on the customer QoS markings
between the customer network and the CE router ingress and applying the required egress QoS policy on the CE router
Which three statements are correct regarding ping mpls command operations? (Choose three.)
MPLS OAM has to be enabled on the router using the mpls oam command.
They use a 127/8 address as the destination address in the MPLS echo request packet.
They use ICMP echo request and ICMP echo reply packets.
They are used to test for a broken LSP.
If there is a broken LSP, instead of using label switching, the packet can still be forwarded based on the destination IP address in the mpls ping echo request packet.
Which three conditions can occur when metering traffic using a dual token bucket traffic policing QoS mechanism on Cisco routers? (Choose three.)
conform
pass
violate
exceed
burst
When configuring LLQ (strict priority queue) on a traffic class using the Cisco IOS XR priority command on a Cisco ASR9K router, which additional QoS command is required for this traffic class?
shape
police
random-detect
bandwidth
Which four pieces of information are stored for each prefix in the LFIB? (Choose four.)
local label
outgoing label
next-hop IP address
outgoing interface
Layer 2 header rewrite information
When implementing MPLS TE tunnels on Cisco IOS XR routers, what is the tunnel setup and hold priority value range, and which value has the highest priority?
0-63, where 0 is the highest priority
0-63, where 63 is the highest priority
0-7, where 0 is the highest priority
0-7, where 7 is the highest priority
In Cisco MPLS TE implementations, what can cause the tunnel bandwidth to adjust automatically based on the traffic load in the tunnel?
fast reroute
admin weight
autobandwidth
bandwidth subpool
Which item is not available to be used for QoS classification in Cisco IOS XR?
MAC SA
protoco
inner EXP
discard-class
QoS-group
F. VLAN
What is an important requirement with MPLS applications like Layer 3 MPLS VPNs?
All the PE routers loopback addresses should be summarized to reduce the number of routing table entries in the core routers.
Targeted hellos are required between all the PE routers.
An end-to-end LSP is required between the PE routers.
The LSPs that are built between the PE routers must be symmetrical (bidirectional).
Which are typical class-based marking policies that are implemented on service provider IP NGN PE routers?
On the PE ingress, classify the customer traffic and then mark with qos-group. On the PE egress, classify based on the qos-group and then mark with mpls exp.
On the PE ingress, classify the customer traffic and then mark with mpls exp. On the PE egress, classify based on the mpls exp and then mark with qos-group.
On the PE ingress, trust the customer QoS markings. On the PE egress, classify based on the customer QoS markings and then mark with qos-group.
On the PE ingress, trust the customer QoS markings. On the PE egress, classify based on the customer QoS markings and then mark with mpls exp.
Which affinity and mask value will match the link affinity that has 0x0F in the first 8 bits and 0x01 in the last
8 bits, and the middle 16 bits can be any value?
affinity 0x0F000001 mask 0x0F000001
affinity 0x0F000001 mask 0x00000000
affinity 0x0F000001 mask 0x11111111
affinity 0x0F000001 mask 0x11000011
affinity 0x0F000001 mask 0xFF0000FF
LDP session protection uses which one to maintain the LDP session between LDP neighbors?
LDP NSF
LDP NSR
backup-targeted LDP hellos
BFD
Which Cisco IOS XR high-availability feature is used to prevent routes from being used before LDP converges?
LDP session protection
LDP-IGP synchronization
BFD
IGP session protection
In which two Cisco IOS XR configuration modes can mpls ldp igp sync be configured? (Choose two.)
config-ldp
config-if
config-ospf-ar
config-ospf
config-isis
When troubleshooting LDP operations on the Cisco IOS and IOS XE routers, what is one of the first things that should be verified?
if running OSPF as the IGP, ensure that OSPFv3 has been enabled
check if the ip cef command has been enabled
verify in the running configurations that all of the required LDP interfaces are defined under the mpls ldp command configuration mode
verify if there are any access lists that are denying TCP and UDP port 464 packets
Which two statements are correct in describing ISP environments that are running IP/MPLS in the core network? (Choose two.)
On the PE routers, each BGP route must use a unique label to reach the BGP next hop.
The BGP next hops point to the PE routers, and only the PE routers are required to run BGP.
A full mesh of IBGP sessions are required between all of the PE and P routers to ensure proper packets forwarding.
The PE and P routers run LDP to learn the labels for reaching the BGP next-hop addresses.
Which Cisco IOS XR command should be used in order to enable LDP on all interfaces for which the IGP protocol is enabled?
RP/0/0/CPU0:R1(config-ospf)#mpls ldp auto-config
RP/0/0/CPU0:R1(config-ospf)#mpls ldp interface all enable
RP/0/0/CPU0:R1(config-ospf)#enable all
RP/0/0/CPU0:R1(config-ldp)#enable all
Which Cisco IOS XR command should be used in order to enable LDP-IGP synchronization for the ISIS IGP protocol?
RP/0/RSP0/CPU0:R1(config-isis-if-af)#mpls ldp sync
RP/0/RSP0/CPU0:R1(config-isis)#mpls ldp sync
RP/0/RSP0/CPU0:R1(config-ldp)#isis ldp sync
LDP-IGP synchronization is not supported for the ISIS IGP protocol on Cisco IOS XR platforms
Layer 2 VPN services that are offered by traditional service providers using a SONET/SDH backbone can be implemented by service providers using an IP/MPLS backbone with which MPLS feature?
LSP stitching
AToM
virtual private WAN services
cell-mode MPLS
Implementing IPoDWDM interfaces on Cisco CRS routers eliminates the need for which network component?
ROADM
external transponders
electrical-optical-electrical converters
electrical cross-connect
Which three steps are required to configure QPPB on Cisco IOS XR routers? (Choose three.)
Apply a QPPB route policy to the BGP process using the table-policy command
Apply a QPPB route policy to the BGP neighbor using the route-policy command
Define a QPPB route policy to match the customer routes, then set the IP precedence or qos- group
Define a QPPB route policy to match the customer IP precedence or qos-group markings, then set the BGP community
Enable QPPB on an interface using the ipv4 bgp policy propagation input ip-precedence|qos- group destination|source command
What is the correct formula for determining the CIR?
CIR = Bc/Tc
CIR = Bc x Tc
CIR = Tc/Bc
CIR = Bc + Be
CIR = Tc/(Bc+Be)
Which two of the following statements are correct regarding LSPs? (Choose two.)
An LSP is created for every routing protocol entry.
Each LSP is bidirectional, that is, packets traveling in the opposite direction use the same LSP.
An IGP is used to populate routing tables in all routers in an MPLS domain.
LDP is used to propagate labels and build LSPs.
The FIB is used to forward MPLS-labeled packets down an LSP.
Which QoS mechanism is used for congestion avoidance?
LLQ
CBWFQ
WRED
LFI
traffic policing
When defining an explicit MPLS TE tunnel path, which two command options are available under the explicit-path configuration mode? (Choose two.)
exclude-address
include-address
next-address
dynamic-address
On a Cisco IOS XR router, which mechanism protects the router resources by filtering and policing the packets flows that are destined to the router that is based on defined flow-type rates?
LLQ
LPTS
Committed Access Rate
Control Plane Policing
Management Plane Protection
Cisco MPLS TE resource attributes that are configured locally for each link are distributed to the headend router of the traffic engineering tunnel using which protocol?
BGP
MP-BGP
LDP
RSVP
OSPF or ISIS with TE extension
DS-TE implementations on Cisco routers support which bandwidth pool(s) and class type(s)? (Choose two.)
global pool only
subpool only
global pool and subpool
class-type 0 only
E. class-type 1 only
class-type 0 and class-type 1
