Network Security

Question 1

BGP Route hijacks

Answer 1

ASes believe other ASes routing advertisements, allowing an AS to hijack routes

Question 2

DNS Reflection

Answer 2

Distributed Denial of Service

Question 3

Security Components

Answer 3

Confidentiality
Integrity
Availability
Authenticity

Question 4

Confidentiality

Answer 4

Information only provided to authorized parties

Question 5

Integrity

Answer 5

Information isnt changed in storage / transit

Question 6

Availability

Answer 6

Information accessible when needed

Question 7

Authenticity

Answer 7

Information origin is accurate

Question 8

Threat

Answer 8

Potential violation of security components

Question 9

Attack

Answer 9

Action that violates a security component

Question 10

Routing Security

Control Plane Authentication

Answer 10

Session
Path
Origin

Question 11

DNS Masquerade

Answer 11

Spoof DNS Server IP address

Provide name:IP mapping to attackers address

Question 12

Session Authentication

Answer 12

ASes send message, and message hash ( md5(message,key))

Question 13

Kaminsky Attack

Answer 13

DNS attack where attack sends fake DNS requests to recursive server.

When recursive server queries authoritative server for answer, attacker responds first, winning the race condition.

Attackers response has NS match in it, poisoning the cache

Question 14

DNS Poison defenses

Answer 14

ID randomization
Source Port randomization
0x20 (random hostname capitalization)

Question 15

DNS Sec

Answer 15

Adds authentication to DNS protocol to allow devices to confirm identity of senders

Question 16

What does BGPSec protect against?

Answer 16

Attacker claiming to be neighbor

AS claiming to be origin for subnet

AS claiming untrue path to subnet

Prevented with a chain of signed paths

Question 17

How is BGP hijacking made undetectable

Answer 17

Attacking AS does not decrement the TTL

Question 18

Calculate Attack Rate

Answer 18

(num IP Addresses / 2^32) * num backscatter packets = total attack rate

or

num backscatter = attack rate * (2 ^ 32 / num IP addresses)

Question 19

BGP manipulation

Answer 19

BGP does not validate information, so can be manipulated

Question 20

Origin Authentication manipulation

Answer 20

AS cant claim victim’s prefix

CAN announce path that ends at proper AS

Question 21

soBGP manipulation

Answer 21

verifies path exists

CAN advertise unavailable path

Question 22

S-BGP manipulation

Answer 22

uses path verification

CAN have shorter more expensive path announced, but forward traffic on longer cheaper route

Question 23

Data plane verification manipulation

Answer 23

Manipulator must forward traffic on path he is announcing

Question 24

Defensive filtering manipulation

Answer 24

Eliminates attacks from stubs

Question 25

3 categories of DNS attacks

Answer 25

Off path ( attackers have to guess)
On path (attackers forge replies)
In line (attackers capture legitimate requests)