WAN Flashcards

1
Q

connectionless WAN system

A

i.e. internets

carries full addressing info in each packet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

connection oriented WAN system

A
  • predetermines packet’s route

- each packet only carries an identifier such as Data Link Connection Identifiers (DLCIs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

metro ethernet

A

use IP aware ethernet switches in the service provider’s network cloud to offer converged voice, data, and video services at ethernet speeds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

3 classes of VPN protocols

A

carrier protocol-protocol over which info travels (frame-relay, ATM, MPLS)

encapsulation protocol-protocol that is wrapped around data (GRE, IPsec, L2F, PPTP, L2TP_

passenger protocol-protocol over which original data was carried (IPX, Appletalk, IPv4/6)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

HMAC

A

keyed hashed message authentication code

-data integrity algorithm used by VPNs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

VPN Authentication methods

A

PSK (pre-shared key) secret key is shared between 2 parties using secure channel

RSA signature: uses exchange of digital certificates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

4 IPsec squares administrators must fill

A
  • IPsec protocol
  • encryption algorithm
  • authentication algorithm
  • DH (diffie-hellman) group which handles key exchange
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

CPE

A

Customer premises equipment, self explanatory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Demarcation point

A

Where service providers responsibility ends and CPE begins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Local loop

A

Connects demarc to central office

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Digital signal 0(DS0)

A

64 Kbps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

T1

A

DS1, containes 24 DS0 circuits, 1.544 Mbps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

E1

A

European equivalent of t1, 2.048 Mbps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

T3

A

DS3
28 DS1’s or 672 DS0’s
44.736 Mbps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

OC-3

A

Optical carrier 3
Fiber
3 DS3’s
155.52 Mbps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

OC-12

A

4 OC-3’s

622.08 Mbps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

OC-48

A

4 OC-12’s

2488.32 Mbps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Frame relay

A

Packet switched

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

ISDN

A

Integrated services digital network
Uses phone lines
Faster than pots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

HDLC

A

High-level data-link control

Data link protocol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

PPP

A

Point to point protocol
Uses link control protocol(lcp)
To manage data link connections

Network control protocol(ncp) is used to allow multiple upper layer protocols to be used

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

PPPoE

A

Point to point protocol over ethernet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

LCP

A

Link control protocol

Method of establishing, configuring, and maintaining and terminating point to point connections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

NCP

A

Network control protocol

Method of establishing and configuring different network layer protocols for transport across the PPP link

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

LCP configuration options

A
Authentication
Compression
Error detection
Multilink
PPP callback
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

PPP session establishment steps

A

Link-establishment phase
Authentication phase(if used)
Network layer protocol phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Frame relay access rate

A

Maximum speed at which frame relay interface can transmit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Frame relay CIR

A

Committed information rate

Max bandwidth of data guaranteed to be delivered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Configure frame relay on Cisco router

A

Use encapsulation frame-relay command on serial interface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

DLCI

A

Data link connection identifiers

Identifies the virtual circuit in frame relay circuita

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Inverse ARP (IARP)

A

Maps a known DLCI to an IP address

32
Q

Commonly used frame relay show commands

A

Show frame-relay lmi, PVC, and map

33
Q

PVC status active

A

Switch is correctly programmed with the DLCI and there is a successful DTE-to-DTE circuit(router to router)

34
Q

PVC status inactive

A

Router is connected to the switch(DTE to DCE) but there’s not a connection to the far end router (DTE)

Can be a router or switch issue

35
Q

PVC status deleted

A

The router(DTE) is configured for a DLCI that the switch (DCE) does not recognize or is not configured correctly

36
Q

Troubleshooting frame relay

A

Check encapsulation type (Cisco or ietf) matches

Check frame relay mappings

Check to see if broadcasts need to be allowed (they aren’t on by default) for routing updates

37
Q

Layer 2 forwarding(L2F)

A

Cisco proprietary tunneling protocol

Old

38
Q

Point-to-point tunneling protocol(PPTP)

A

Created by Microsoft to allow secure transfer of data from remote networks to the corporate network

39
Q

Layer 2 tunneling protocol(L2TP)

A

Creates by Cisco and Microsoft to replace L2F and PPTP. Merged the capabilities of both L2F and PPTP into one protocol

40
Q

generic routing encapsulation(GRE)

A

Cisco proprietary tunneling protocol. Forms virtual point-to-point links, allowing a variety of protocols to be encapsulated in IP tunnels

41
Q

2 primary IPSec security protocols

A
Authentication header(ah)
Encapsulating security payload(ESP)
42
Q

4 services of ESP encapsulating security payload

A

Confidentiality
Data origin authentication and connection less integrity
Anti-replay service
Traffic flow

43
Q

Which interface provides clocking, DTE or DCE?

A

DCE

44
Q

command used to view physical information about serial interface, such as the type of cable connected

A

show controller interface #

45
Q

command to set serial encapsulation to HDLC

A

in interface configuration mode

encapsulation HDLC

46
Q

What are the 3 basic components of PPP

A

A method for encapsulating multiprotocol datagrams
An LCP for establishing, configuring, and testing the data-link connection
A family of NCP for establishing and configuring different network layer protocols

47
Q

command to set serial interface in PPP mode

A

encapsulation ppp

48
Q

What is PAP?

A

password authentication protocol

username and password sent in cleartext

49
Q

2 types of devices connected frame relay network

A

DTE - customer side

DCE - service providor side, provides clocking

50
Q

What does local access rate mean in Frame Relay parlance?

A

The connection speed from the local loop to the frame relay cloud

51
Q

What is a PVC?

A

permanent virtual circuit, for frame-relay

52
Q

What is an SVC?

A

switched virtual circuit, for frame-relay but most commonly used in X.25 circuits.

53
Q

What is a DLCI?

A

The DLCI contains a 10-bit number in the address field of the Frame Relay frame header that identifies the VC. DLCIs have only local significance because the identifier references the point between the local router and the local Frame Relay switch to which the DLCI is connected

54
Q

What is the frame relay CIR?

A

committed information rate

specifies the maximum average data rate that the network undertakes to deliver under normal conditions.

55
Q

What is inverse ARP?

A

used in frame relay to discover the network address of the remote DTE from the DLCI. maps DLCI to IP

56
Q

what is LMI in frame relay?

A

Local Management Interface. Set of enhancements to the basic Frame Relay specification. LMI includes support for a keepalive mechanism, which verifies that data is flowing; a multicast mechanism, which provides the network server with its local DLCI and the multicast DLCI; global addressing, which gives DLCIs global rather than local significance in Frame Relay networks; and a status mechanism, which provides an on-going status report on the DLCIs known to the switch. Known as LMT in ANSI terminology.

57
Q

formula to calculate the number of PVCs needed for a full mesh frame relay topology

A

The formula n x (n - 1) / 2 describes how to calculate the total number of links that are required to achieve a full-mesh topology, where n is the number of nodes. In a small network of 4 nodes, only 6 PVCs are required: 4 x (4 - 1) / 2 = 6.

58
Q

How to prevent spoke routers from becoming OSPF BDR over frame relay

A

configure the interface facing the hub with a priority of 0

59
Q

How to configure hub router interface to avoid split horizon issues?

A

use multiple point to point subinterfaces

60
Q

what number assignments are possible for DLCIs?

A

DLCI numbers 0 (zero) and 1023 are reserved for management.
DLCI numbers 1 to 15 and 1008 to 1022 are reserved for future use.
DLCI numbers 992 to 1007 are reserved for Layer 2 management of Frame Relay bearer service.
DLCI numbers 16 to 991 are assigned to customer endpoints in a Frame Relay network.

61
Q

what are the 3 LMI types?

A

Cisco
ANSI
Q.933A

62
Q

what are the 3 possible frame-relay VC statuses?

A

Active: Indicates that the VC connection is active and that routers can exchange data over the Frame Relay network
Inactive: Indicates that the local connection to the Frame Relay switch is working, but the remote router connection to the remote Frame Relay switch is not working
Deleted: Indicates that either no LMI is being received from the Frame Relay switch, or there is no service between the router and the local Frame Relay switch

63
Q

In what situations to you need to configure static frame-relay mappings

A

A Frame Relay peer does not support Inverse ARP.
You want to control broadcast traffic across a PVC.
You need to support different Frame Relay encapsulations across PVCs.

64
Q

how to configure point to point frame relay subinterfaces

A

To configure point-to-point Frame Relay subinterfaces, first enable Frame Relay encapsulation on the physical interface. Then create a point-to-point subinterface and assign an IP address, bandwidth, and DLCI to the subinterface

65
Q

command to bind DLCI to frame relay subinterface

A

frame-relay interface-dlci dlci#

66
Q

BR1(router)# interface Serial0/0/0
BR1(router-if)# no ip address
BR1(router-if)# encapsulation frame-relay
BR1(router-if)# no shutdown
BR1(router-if)# interface Serial0/0/0.210 point-to-point
BR1(router-subif)# ip address 10.1.1.2 255.255.255.252
BR1(router-subif)# bandwidth 256
BR1(router-subif)# frame-relay interface-dlci 210

A

BR1(router)# interface Serial0/0/0
BR1(router-if)# no ip address
BR1(router-if)# encapsulation frame-relay
BR1(router-if)# no shutdown
BR1(router-if)# interface Serial0/0/0.210 point-to-point
BR1(router-subif)# ip address 10.1.1.2 255.255.255.252
BR1(router-subif)# bandwidth 256
BR1(router-subif)# frame-relay interface-dlci 210

67
Q

process to configure multipoint frame relay subinterfaces

A

When configuring Frame Relay multipoint subinterfaces, first enable Frame Relay encapsulation on the physical interface. Then create a multipoint subinterface and assign an IP address and bandwidth. Create static mappings between IP addresses and DLCIs using the frame-relay map command.

68
Q

What is IPSEC?

A

a framework of open standards that can provide security for a VPN. The IPsec framework is algorithm-independent and is not bound to any specific encryption, authentication, security algorithms, or keying technology

69
Q

What are the 4 critical functions IPSEC provides?

A

confidentiality
data integrity
authentication
antireplay protection

70
Q

what protocol does IPSEC use to authenticate peers?

A

IKE (internet key exchange)

71
Q

What are the headers a tunnel interface supports?

A

A passenger protocol or encapsulated protocol such as IPv4 or IPv6. This protocol is the one that is being encapsulated.
A carrier or encapsulation protocol (GRE, in this case).
A transport delivery protocol, such as IP, which is the protocol that carries the encapsulated protocol.

72
Q

What is GRE?

A

Generic Routing Encapsulation. Tunneling protocol that was developed by Cisco and that can encapsulate a variety of protocol packet types inside IP tunnels. This process creates a virtual point-to-point link to Cisco routers at remote points over an IP network.

73
Q

steps necessary to configure a GRE tunnel

A

Branch(config)#interface Tunnel 0
Branch(config-if)#tunnel mode gre ip
Branch(config-if)#ip address 192.168.2.1 255.255.255.0
Branch(config-if)#tunnel source 209.165.201.1
Branch(config-if)#tunnel destination 209.165.202.130

74
Q

When adding a GRE tunnel to an OSPF routing process, what additional step is required?

A

set the bandwidth to ensure proper routing metrics

75
Q

Command to verify a GRE tunnel state

A

show interface tunnel tunnel#