Ccnp Route, Chapter 22 - Connecting The Branch Office

Front 1

What are some of the options on how to connect a branch office to an enterprise office?

Back 1

• Leased Lines
• Frame-relay
• MPLS
• VPNs
• Metro Ethernet
• More

Front 2

Leased Lines, Frame-relay, MPLS, VPNs, and Metro Ethernet all have one thing in common. What is it?

Back 2

They are all private

Front 3

What is a way to connect branch offices using public connections

Back 3

DSL and Cable modems

Front 4

What is the main difference between public and private connections?

Back 4

When we use public connections we need to think more about security.

Front 5

If we are using IPv4 what do we need to configure to make sure our devices can reach the internet?

Back 5

NAT

Front 6

If you have a single router connected to the enterprise network via a router what are some things you should configure?

Back 6

• Interface (prob DSL or Cable)
• Default Route
• NAT
• DHCP
• IOS Firewall
• IPSEC VPN tunnel (protect data)
• Integrated switch ports on the router

Front 7

What does the Cisco ISR stand for?

Back 7

Integrated Services Router

Front 8

What does the Cisco ISR do ?

Back 8

routers offer more than just routing; you can have a
built-in switch
IOS Firewall
IPSEC VPN
Wireless
VoIP all in a single box

Front 9

With a medium size branch what kind of connection would you use?

Back 9

Private

Front 10

What are some things to consider when setting up a medium size branch office?

Back 10

• Private Services
• Routing
• Small Branch Office

NOTE:

Larger branch offices have more redundacy

Front 11

What does broadband mean today.

Back 11

It is used for any high speed Internet Access

• DSL
• Cable
• Wireless

Front 12

Ethernet does not offer __________________.

Back 12

Authentication

Front 13

What do Broadband ISP's often use to offer authentication?

Back 13

PPPOE

PPP over Ethernet

Front 14

What are some forms of PPP Authentication?

Back 14

• PAP
• CHAP

NOTE:

These are used to identify the customer and use accounting to log statistics

Front 15

What do DSL ISP's use for authentication?

Back 15

PPPoA

PPP over ATM

Front 16

If you get a dynamic public IP address and you configure DHCP, what protocols need to be configured?

Back 16

It will require NAT in combination with PAT to make sure that our hosts can access the Internet.

Front 17

What are some security options to protect a branch router form the outside world?

Back 17

(Reflexive) Access-List
IOS Firewall

Front 18

What is (Reflexive) Access-List?

Back 18

This is really the "poor man's" firewall to protect your router.

NOTE:

A reflexive access-list can be used to drop all traffic from the Internet unless it originated from the inside.

Front 19

What is an IOS Firewall?

Back 19

Cisco ISR routers are able to use Context Based Access Control (CBAC), XBF (Zone Based Firewall) and even IPS feature (Intrusion Prevention System)

Front 20

To stop from having to change the firewall rules in your network every time you get a new dynamic address what can you do?

Back 20

Use Tunneling between the branch router and the enterprise network.

Front 21

If you use a tunnel between the branch and enterprise packet how does it send the IP packet?

Back 21

• It will encrypt the IP Packet carrying the data
• Put it into another IP Packet (this packet will have the branch routers IP address as the source and the CPN Server at the enterprise network)

Front 22

When the VPN server receives and IP packet sent through tunneling. What happens?

Back 22

• it will decrypt the IP packet
• Check Security Header to confirm its from the branch office

Front 23

What is IPSEC?

Back 23

It is a framework that defines what we exactly do with the tunnel.

EXAMPLE:
We can choose between 3DES or AES for encyption, pre-shared key or certificates and more.

Front 24

With a simple setup the router has 2 decisions to make what are they?

Back 24

• Send packet through a tunnel
• Send packet to ISP after performing NAT

Front 25

When you have medium to large branch offices what are the two options when it comes to routing?

Back 25

• Use static Routes
• Use IGP like OSPF or EIGRP

Front 26

When we use IGP and we run into the problem IPSEC doesn't support multicast traffic what is the solution?

Back 26

We can use GRE (Generic Routing Encapsulation) tunnel that runs over the IPSEC tunnel

Front 27

How does GRE support multicasts

Back 27

Generic Routing Encapsulation

By encapsulating it in unicast packets so that's how we can tunnel IGP's

Front 28

Name 4 features of GRE?

Back 28

• Tunneling of Protocols (IPv4,IPv6, more)
• Acts like layer 3 point-to-point
• Support for tunneling multicast and broadcast traffic
• tunnels can be encrypted

Front 29

How does GRE act like a layer 3 point-to-point protocol?

Back 29

Generic Routing Encapsulation

You can configure IP addresses on the tunnel interface.

Front 30

What can GRE tunnels be encrypted with?

Back 30

Generic Routing Encapsulation

IPSEC to make secure tunnels

Front 31

When we configure a GRE tunnel we will have two layer 3 paths that the router can choose from:

Back 31

• Through the GRE Tunnel
• The WAN connection

Front 32

If a Branch has a GRE tunnel and a Leased line configured what do Network Engineers often choose as their primary.

Back 32

Leased Line is Primary

GRE as the backup

Front 33

What does it mean to implement a floating static route?

Back 33

If the leased line fails the routing information from the IGP will be removed from the routing table and the static routing will be inserted.

Front 34

What is a telco local loop?

Back 34

Used in DSL

This is the phone line between the customer site and the phone company facility.

NOTE:

It uses the same phone line as what we have been using for analog phones.

Front 35

Analog phones use the frequency

Back 35

below 4000Hz

Front 36

The digital signal for DSL uses the frequency

Back 36

above 4000 Hz

Front 37

How does the telephone company separate voice and DSL?

Back 37

DSLAM

Digital Subscriber Line Access Multiplexor

Front 38

How does a DSLAM work?

Back 38

It will split the analog single to a voice switch that handles voice and the digital signal to the router.

Front 39

What is ATM?

Back 39

Asynchronous Transfer Mode

This is an older protocol that controls the physical data link layer when using DSL.

Front 40

Why would you use PPP over ATM?

Back 40

Chap Authentication

Front 41

Where does the ATM PVC run?

Back 41

It runs between the DSL modem and the ISP router

NOTE:

This PVC is similar to Frame-relay

Front 42

What is the difference between ATM PVC and Frame-relay PVC?

Back 42

Frame-relay uses DLCI to identify the PVC and ATM uses something similar called VPI/VCI

Virtual Path Identified/Virtual Connection Identifier

Front 43

What are the 5 things that must happen to configure DSL?

Back 43

1. Configure a dialer Interface
2. Apply PPP Configuration to the ATM interface
3. Apply ATM interface to the dialer interface
4. Link the ATM interface to the dialer interface
5. Configure a default route to route traffic out of the dialer interface

Front 44

In DSL what command tells the dialer interface that when it wants to setup a connection, it has to use a member interface of the "dialer pool"?

Back 44

"dialer pool" command

Front 45

Are VPI/VCI the same numbers everytime?

Back 45

No, you must contact your service provider to find out these values?

Front 46

What is the final step to activate a crypto map?

Back 46

You must apply it to the interface.