Ccie R&s Written Mpls

Front 1

MPLS

Back 1

multiprotocol label switching

Front 2

MPLS is an _____ standard

Back 2

OPEN

Front 3

What RFC defines MPLS?

Back 3

RFC 3031

Front 4

MPLS was previously Cisco proprietary ______________

Back 4

tag switching

Front 5

the multiprotocol in MPLS allows

Back 5

transport of different payloads

Front 6

MPLS can move Layer 2 at

Back 6

Ethernet
Frame Relay
ATM

Front 7

MPLS can move Layer 3 at

Back 7

IPv4
IPv6

Front 8

Label switching -

Back 8

switches traffic between interfaces based on local significant label values

Front 9

MPLS label switching is similar to how..

Back 9

Frame Relay or ATM switch uses input/output DLCIs and VPI/VCIs

Front 10

Why use MPLS?

Back 10

Transparent tunneling over SP Network
BGP free core
saves routing table space on provider routers
traffic engineering

Front 11

traffic engineering

Back 11

distribute load over underutilized links
give bandwidth guarantees and detect failures quickly

Front 12

MPLS offers _______ service to customers.

Back 12

L2/L3 VPN

Front 13

how many bytes is the MPLS header

Back 13

4

Front 14

MPLS header is used to

Back 14

switch packets

Front 15

MPLS Label stack encoding (RFC 3032)

Back 15

20 bit Label (locally significant)
3 bit EXP (class of service)
BoS bit (defines last label in the label stack)
8 bit TTL (time to live)

Front 16

BoS

Back 16

bottom of stack bit

Front 17

MPLS labels are bound to _____

Back 17

FECs (forwarding equivalency class)

Front 18

Router uses the MPLS _____ instead of CEF FIB or IP routing table to switch traffic

Back 18

LFIB (label forwarding info base)

Front 19

MPLS switching logic

Back 19

If traffic comes in if1 with label X send it out if2 with label Y

Front 20

IPv4 prefix and label can define the ____

Back 20

FEC

Front 21

FEC definition

Back 21

a group of packets that possess the same label and are all forwarding through the infrastructure in a common way

Front 22

MPLS network consists of

Back 22

PE/LER devices
P /LSR devices

Front 23

PE /LER device properties

Back 23

provider edge router/label edge router
connect to customer edge (CE) devices
receive unlabeled packets (like IPv4) and add label
performs ip routing and MPLS lookups

Front 24

add label to unlabeled packet

Back 24

AKA label push or label imposition

Front 25

P/LSR device properties

Back 25

provider router/label switch routers
connects to PEs and/or other P routers
switch traffic based only on MPLS label

Front 26

MPLS PE and P router three major operations

Back 26

Label Push
Label Swap
Label Pop

Front 27

Label Push

Back 27

add a label to an incoming packet
AKA label imposition

Front 28

Label Swap

Back 28

replace the label on an incoming packet

Front 29

Label pop

Back 29

remove the label from an outgoing packet
AKA label disposition

Front 30

The ip prefix and the layer 2 circuit typically make up the _____

Back 30

FEC

Front 31

If a core MPLS router receives a labeled packet and there is no entry in the LFIB, the router does what?

Back 31

drop the packet

Front 32

Penultimate meaning

Back 32

next to last

Front 33

PHP

Back 33

Penultimate Hop Popping

Front 34

Label mapping information is advertised using a

Back 34

Label distribution protocol

Front 35

TDP

Back 35

Tag distribution protocol

Front 36

TDP uses what port for UDP broadcast to discover neighbors?

Back 36

711

Front 37

TDP uses what TCP port to setup a session after discovering neighbor

Back 37

711

Front 38

LDP

Back 38

label distribution protocol

Front 39

LDP uses UDP multicast to what group address

Back 39

224.0.0.2

Front 40

What UDP port is used with LDP for neighbor discovery?

Back 40

646

Front 41

What TCP port is used LDP for session setup between neighbors?

Back 41

646

Front 42

By default, the IP TTL is copied into the MPLS

Back 42

TTL field

Front 43

MPLS VPN two basic components

Back 43

Separation of customer routing information

Exchange of customer routing information

Front 44

VRF

Back 44

Virtual Routing and Forwarding

Front 45

Each VRF has its own

Back 45

routing table

Front 46

Routing inside a VRF

Back 46

static routes
RIP
EIGRP
OSPF
IS-IS
MP-BGP
Policy routing

Front 47

How do PE routers exchange VRF info?

Back 47

MP-BGP (VPNv4)

Front 48

VPNv4 uses ___ byte route distinguisher

Back 48

8
unique per VPN or per VPN site

Front 49

VPNv4 uses ___ byte IP address

Back 49

4
Unique per VPN

Front 50

VPNv4 does include the MPLS label

Back 50

True

Front 51

route distinguisher used solely to make routes

Back 51

unique

Front 52

BGP extended community "route-target" used to control what enters/exits...

Back 52

VRF table

Front 53

export route target

Back 53

what routes will go from VRF into BGP

Front 54

import route target

Back 54

what routes will go from BGP into VRF

Front 55

allows control on a per prefix basis importing/exporting routes on VRF

Back 55

import/export map

Front 56

BGP Extended community byte size

Back 56

8

Front 57

VPNv4 speakers only accept VPNv4 routes with a route-target matching a local....

Back 57

VRF