Challenges in Inferring Spoofed Traffic at IXPs Matthew Luckie - - PowerPoint PPT Presentation

challenges in inferring spoofed traffic at ixps
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Challenges in Inferring Spoofed Traffic at IXPs Matthew Luckie - - PowerPoint PPT Presentation

Challenges in Inferring Spoofed Traffic at IXPs Matthew Luckie Bradley Huffaker Lucas Mller University of Waikato CAIDA/UC San Diego UFRGS/CAIDA Kc Claffy Marinho Barcellos CAIDA/UC San Diego UFRGS/University of Waikato ACM CoNEXT


slide-1
SLIDE 1

Challenges in Inferring Spoofed Traffic at IXPs

Lucas Müller


UFRGS/CAIDA

Matthew Luckie

University of Waikato

Bradley Huffaker

CAIDA/UC San Diego

Kc Claffy

CAIDA/UC San Diego

Marinho Barcellos

UFRGS/University of Waikato

ACM CoNEXT 2019 — Orlando, Florida, U.S.A. December 9-12, 2019

slide-2
SLIDE 2

2

Broader visibility of networks that 
 do not filter spoofed packets

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SLIDE 3

3

Consequences:
 spoofed denial-of-service (DoS) attacks

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SLIDE 4

3

Consequences:
 spoofed denial-of-service (DoS) attacks

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SLIDE 5

3

Consequences:
 spoofed denial-of-service (DoS) attacks

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SLIDE 6

3

Consequences:
 spoofed denial-of-service (DoS) attacks

slide-7
SLIDE 7

4

IP Spoofing

IPv4 header

Architectural limitation that provides an attacker with the ability to send packets using spoofed source IP addresses

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SLIDE 8

4

IP Spoofing

IPv4 header

Architectural limitation that provides an attacker with the ability to send packets using spoofed source IP addresses

IETF introduced Best Current Practices (BCPs) recommending that networks block these packets — i.e., implement 
 Source Address Validation (SAV)

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SLIDE 9

4

IP Spoofing

IPv4 header

Architectural limitation that provides an attacker with the ability to send packets using spoofed source IP addresses

IETF introduced Best Current Practices (BCPs) recommending that networks block these packets — i.e., implement 
 Source Address Validation (SAV)

  • Compliance with these filtering practices

has misaligned incentives

  • Deploying SAV is primarily for the benefit
  • f other networks
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SLIDE 10

5

Remediation and Policy Interventions

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SLIDE 11

5

Remediation and Policy Interventions

We need to identify networks lacking SAV deployment, but doing this is challenging at Internet scale

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SLIDE 12

5

Remediation and Policy Interventions

We need to identify networks lacking SAV deployment, but doing this is challenging at Internet scale

  • Definitive method requires an active probing

vantage point in each network being tested

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SLIDE 13

5

Remediation and Policy Interventions

We need to identify networks lacking SAV deployment, but doing this is challenging at Internet scale

  • Definitive method requires an active probing

vantage point in each network being tested

  • ~65K independently routed networks

CAIDA's 2017 visualization of IPv4 Internet topology at the Autonomous System (AS) level

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SLIDE 14

5

Remediation and Policy Interventions

We need to identify networks lacking SAV deployment, but doing this is challenging at Internet scale

  • Definitive method requires an active probing

vantage point in each network being tested

  • ~65K independently routed networks
  • Limited feasibility for a comprehensive

assessment of Internet spoofing

CAIDA's 2017 visualization of IPv4 Internet topology at the Autonomous System (AS) level

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SLIDE 15

6

Remediation and Policy Interventions

Broader visibility may lie in the capability to infer lack of SAV compliance from aggregated Internet traffic data

700+ Internet Exchange Points (IXP)

[PeeringDB, 2019]

We need to identify networks lacking SAV deployment, but doing this is challenging at Internet scale

  • Definitive method requires an active probing

vantage point in each network being tested

  • ~65K independently routed networks
  • Limited feasibility for a comprehensive

assessment of Internet spoofing

slide-16
SLIDE 16
  • ur goal

design and develop a methodology 
 to identify spoofed traffic crossing an IXP and infer lack of SAV

7

slide-17
SLIDE 17

8

slide-18
SLIDE 18

Contributions

9

slide-19
SLIDE 19

Contributions

9

  • 1. Challenges

Provide detailed analysis of methodological challenges for inferring spoofed packets at IXPs

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SLIDE 20

Contributions

9

  • 1. Challenges

Provide detailed analysis of methodological challenges for inferring spoofed packets at IXPs

  • 2. Methodology

Developed a methodology to classify flows, navigating through all challenges identified

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SLIDE 21

Contributions

9

  • 1. Challenges

Provide detailed analysis of methodological challenges for inferring spoofed packets at IXPs

  • 2. Methodology

Developed a methodology to classify flows, navigating through all challenges identified

  • 3. Observations 


and Lessons

Used our methodology and compare it with the 
 state-of-the-art[1] at 
 an IXP in Brazil, 
 reporting our findings

[1] Lichtblau et al. Detection, Classification, and Analysis of Inter-domain Traffic with Spoofed Source IP Addresses. In: ACM IMC, 2017.

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SLIDE 22

Bird’s Eye View

10

slide-23
SLIDE 23

Bird’s Eye View

10

IXP traffic flow data and topology information

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SLIDE 24

Bird’s Eye View

10

IXP traffic flow data and topology information valid IP address space per Autonomous System (AS)

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SLIDE 25

Bird’s Eye View

10

IXP traffic flow data and topology information valid IP address space per Autonomous System (AS) Classification Pipeline Methodology list of networks with and without SAV, with evidence to support

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SLIDE 26

Challenges: Pieces of the Puzzle

11

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SLIDE 27

Challenges: Pieces of the Puzzle

  • 1. Identify Valid Source Address Space

11

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SLIDE 28

Challenges: Pieces of the Puzzle

  • 1. Identify Valid Source Address Space
  • there is no global registry that contains ground truth

11

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SLIDE 29

Challenges: Pieces of the Puzzle

  • 1. Identify Valid Source Address Space
  • there is no global registry that contains ground truth
  • need to infer the set of valid source addresses


11

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SLIDE 30

Challenges: Pieces of the Puzzle

  • 1. Identify Valid Source Address Space
  • there is no global registry that contains ground truth
  • need to infer the set of valid source addresses

  • 2. Tackle IXP Topology and Traffic Visibility Properties

11

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SLIDE 31

Challenges: Pieces of the Puzzle

  • 1. Identify Valid Source Address Space
  • there is no global registry that contains ground truth
  • need to infer the set of valid source addresses

  • 2. Tackle IXP Topology and Traffic Visibility Properties
  • understand modern IXP interconnection practices

11

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SLIDE 32

Challenges: Pieces of the Puzzle

  • 1. Identify Valid Source Address Space
  • there is no global registry that contains ground truth
  • need to infer the set of valid source addresses

  • 2. Tackle IXP Topology and Traffic Visibility Properties
  • understand modern IXP interconnection practices
  • implications on visibility of both topology and traffic

11

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SLIDE 33
  • 1. Identify Valid Source Address Space

12

IP Address
 Space

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SLIDE 34
  • 1. Identify Valid Source Address Space

12

IETF Reserved 
 Bogons

Usable IP Address
 Space

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SLIDE 35
  • 1. Identify Valid Source Address Space

12

Unassigned Routed

IETF Reserved 
 Bogons

Usable IP Address
 Space

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SLIDE 36
  • 1. Identify Valid Source Address Space

12

Unassigned Routed

IETF Reserved 
 Bogons

Usable IP Address
 Space

Inferred based on BGP data and 
 the links established by each AS

slide-37
SLIDE 37
  • 1. Identify Valid Source Address Space

12

Unassigned Routed

IETF Reserved 
 Bogons

Usable IP Address
 Space

Inferred based on BGP data and 
 the links established by each AS Define the set of ASes a given AS can reach through its customers Customer Cones

slide-38
SLIDE 38
  • 2. Tackle IXP Topology and Traffic Visibility Properties

13

Focus on understanding operational complexities of the vantage point

168.228.252.0/22 200.17.80.0/20 200.132.59.0/24 200.236.32.0/19 200.19.0.0/21 200.238.0.0/18 … 13.32.136.2/23 52.216.180/24 75.2.82.0/24 161.38.206.0/23 216.137.62.0/24 … AS64505 Prefix-level Customer Cone Amazon’s AS Prefix-level Customer Cone

IXP

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SLIDE 39
  • 2. Tackle IXP Topology and Traffic Visibility Properties

13

Focus on understanding operational complexities of the vantage point

168.228.252.0/22 200.17.80.0/20 200.132.59.0/24 200.236.32.0/19 200.19.0.0/21 200.238.0.0/18 … 13.32.136.2/23 52.216.180/24 75.2.82.0/24 161.38.206.0/23 216.137.62.0/24 … AS64505 Prefix-level Customer Cone Amazon’s AS Prefix-level Customer Cone

IXP

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SLIDE 40

Core Switch Legend: IXP switching fabric #X Switch

  • 2. Tackle IXP Topology and Traffic Visibility Properties

14

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SLIDE 41

Core Switch CF #1 CF #2 CF #3 CF #4 Legend: Switch Physical connection CF: Colocation Facility IXP switching fabric #X

  • 2. Tackle IXP Topology and Traffic Visibility Properties

15

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SLIDE 42

Core Switch CF #1 CF #2

AS C AS B

CF #3 CF #4 Legend: Physical connection and VLAN configured to neighbor

AS Z

Autonomous System IXP switching fabric #X

AS D AS A

Switch Physical connection CF: Colocation Facility

  • 2. Tackle IXP Topology and Traffic Visibility Properties

16

slide-43
SLIDE 43

Core Switch CF #1 CF #2

AS C AS B

CF #3 CF #4 Legend:

Res Z

Reseller

AS F AS G Res J

IXP switching fabric #X Stacked VLAN (IEEE 802.1q, QinQ)

AS H AS D AS E

Reseller-Tag: IXP-Tag:

AS A

Physical connection and VLAN configured to neighbor

AS Z

Autonomous System Switch Physical connection CF: Colocation Facility

  • 2. Tackle IXP Topology and Traffic Visibility Properties

17

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SLIDE 44

Core Switch Core Switch CF #1 CF #2

AS C AS B

CF #3 CF #4 Legend: CF #5 CF #6

AS F AS G Res J

IXP switching fabric #X IXP switching fabric #Y

AS H AS D AS E AS E AS A Res Z

Reseller Stacked VLAN (IEEE 802.1q, QinQ) Reseller-Tag: IXP-Tag: Physical connection and VLAN configured to neighbor

AS Z

Autonomous System Switch Physical connection CF: Colocation Facility

  • 2. Tackle IXP Topology and Traffic Visibility Properties

18

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SLIDE 45

Core Switch Core Switch CF #1 CF #2

AS C AS B

CF #3 CF #4 Legend: CF #5 CF #6

M

Connection between metropolitan regions

AS F AS G Res J

IXP switching fabric #X IXP switching fabric #Y

AS H AS D AS E AS E

M

Res K Res K AS A Res Z

Reseller Stacked VLAN (IEEE 802.1q, QinQ) Reseller-Tag: IXP-Tag: Physical connection and VLAN configured to neighbor

AS Z

Autonomous System Switch Physical connection CF: Colocation Facility

  • 2. Tackle IXP Topology and Traffic Visibility Properties

19

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SLIDE 46

Core Switch Core Switch CF #1 CF #2

AS C AS B

CF #3 CF #4 Legend: CF #5 CF #6

AS F AS G Res J

IXP switching fabric #X IXP switching fabric #Y

AS H AS D AS E AS E

M

Res K Res K AS A

and VLAN configured Autonomous

  • 2. Tackle IXP Topology and Traffic Visibility Properties

20

IXP

  • In practice IXPs, CFs and resellers offer complex

services

  • Interconnection practices occur below and are thus

not visible to the IP layer or in the BGP Protocol

  • Must take them into account during the traffic

classification processing

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SLIDE 47

(1) c2p: customer-to-provider (2) p2p: peer-to-peer

A B Pe Cu Pr customer B to provider A D C Pe Cu Pr C D Pe Cu Pr F Pe Cu Pr G H E Pe Cu Pr Pe Cu Pr

peer C to peer D provider E to customer F sibling G to sibling H transits only traffic from its customer cone transits all traffic (3) p2c: provider-to-customer (4) s2s: sibling-to-sibling Pr: Provider Pe: Peer Cu: Customer

X Y Z X Y Z

Legend Y will not transit packets sourced in Z to X. Y will transit packets sourced in Z to X.

  • 2. Tackle IXP Topology and Traffic Visibility Properties

21

Transits only traffic from its customer cone Transits all traffic Transits only traffic from its customer cone Transits only traffic from its customer cone

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SLIDE 48

(1) c2p: customer-to-provider (2) p2p: peer-to-peer

A B Pe Cu Pr customer B to provider A D C Pe Cu Pr C D Pe Cu Pr F Pe Cu Pr G H E Pe Cu Pr Pe Cu Pr

peer C to peer D provider E to customer F sibling G to sibling H transits only traffic from its customer cone transits all traffic (3) p2c: provider-to-customer (4) s2s: sibling-to-sibling Pr: Provider Pe: Peer Cu: Customer

X Y Z X Y Z

Legend Y will not transit packets sourced in Z to X. Y will transit packets sourced in Z to X.

  • 2. Tackle IXP Topology and Traffic Visibility Properties

21

Transits only traffic from its customer cone Transits all traffic Transits only traffic from its customer cone Transits only traffic from its customer cone

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SLIDE 49

(1) c2p: customer-to-provider (2) p2p: peer-to-peer

A B Pe Cu Pr customer B to provider A D C Pe Cu Pr C D Pe Cu Pr F Pe Cu Pr G H E Pe Cu Pr Pe Cu Pr

peer C to peer D provider E to customer F sibling G to sibling H transits only traffic from its customer cone transits all traffic (3) p2c: provider-to-customer (4) s2s: sibling-to-sibling Pr: Provider Pe: Peer Cu: Customer

X Y Z X Y Z

Legend Y will not transit packets sourced in Z to X. Y will transit packets sourced in Z to X.

  • 2. Tackle IXP Topology and Traffic Visibility Properties

21

Transits only traffic from its customer cone Transits all traffic Transits only traffic from its customer cone Transits only traffic from its customer cone

slide-50
SLIDE 50

(1) c2p: customer-to-provider (2) p2p: peer-to-peer

A B Pe Cu Pr customer B to provider A D C Pe Cu Pr C D Pe Cu Pr F Pe Cu Pr G H E Pe Cu Pr Pe Cu Pr

peer C to peer D provider E to customer F sibling G to sibling H transits only traffic from its customer cone transits all traffic (3) p2c: provider-to-customer (4) s2s: sibling-to-sibling Pr: Provider Pe: Peer Cu: Customer

X Y Z X Y Z

Legend Y will not transit packets sourced in Z to X. Y will transit packets sourced in Z to X.

  • 2. Tackle IXP Topology and Traffic Visibility Properties

21

Transits only traffic from its customer cone Transits all traffic Transits only traffic from its customer cone

slide-51
SLIDE 51

(1) c2p: customer-to-provider (2) p2p: peer-to-peer

A B Pe Cu Pr customer B to provider A D C Pe Cu Pr C D Pe Cu Pr F Pe Cu Pr G H E Pe Cu Pr Pe Cu Pr

peer C to peer D provider E to customer F sibling G to sibling H transits only traffic from its customer cone transits all traffic (3) p2c: provider-to-customer (4) s2s: sibling-to-sibling Pr: Provider Pe: Peer Cu: Customer

X Y Z X Y Z

Legend Y will not transit packets sourced in Z to X. Y will transit packets sourced in Z to X.

  • 2. Tackle IXP Topology and Traffic Visibility Properties

21

Transits only traffic from its customer cone Transits all traffic Transits only traffic from its customer cone

slide-52
SLIDE 52

(1) c2p: customer-to-provider (2) p2p: peer-to-peer

A B Pe Cu Pr customer B to provider A D C Pe Cu Pr C D Pe Cu Pr F Pe Cu Pr G H E Pe Cu Pr Pe Cu Pr

peer C to peer D provider E to customer F sibling G to sibling H transits only traffic from its customer cone transits all traffic (3) p2c: provider-to-customer (4) s2s: sibling-to-sibling Pr: Provider Pe: Peer Cu: Customer

X Y Z X Y Z

Legend Y will not transit packets sourced in Z to X. Y will transit packets sourced in Z to X.

  • 2. Tackle IXP Topology and Traffic Visibility Properties

21

Transits only traffic from its customer cone Transits all traffic Transits only traffic from its customer cone

slide-53
SLIDE 53

(1) c2p: customer-to-provider (2) p2p: peer-to-peer

A B Pe Cu Pr customer B to provider A D C Pe Cu Pr C D Pe Cu Pr F Pe Cu Pr G H E Pe Cu Pr Pe Cu Pr

peer C to peer D provider E to customer F sibling G to sibling H transits only traffic from its customer cone transits all traffic (3) p2c: provider-to-customer (4) s2s: sibling-to-sibling Pr: Provider Pe: Peer Cu: Customer

X Y Z X Y Z

Legend Y will not transit packets sourced in Z to X. Y will transit packets sourced in Z to X.

  • 2. Tackle IXP Topology and Traffic Visibility Properties

21

Transits only traffic from its customer cone Transits all traffic

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SLIDE 54

Spoofer-IX Inference Method:
 Putting the Pieces Together

22

Spoofer-IX method

MAC-to-AS mapping traffjc fmow data

list of networks inferred as with and without SAV, with evidence to support IXP data (§5)

bogon prefjxes unassigned prefjxes routable address space per AS

Address space fundamentals(§2.2)

Prefjx-Level Customer Cone Algorithm Traffjc Classifjcation Pipeline AS-Level Customer Cone Algorithm AS Relationship Inference Algorithm prefjx-to-AS mapping AS relationships inferred siblings ASes IXP validation data to check AS-relationships and prefjxes inferred BGP routing data IANA allocated ASes records

Stage 1: Build the Customer Cone

Route Server data Looking Glass Server data

Stage 2: Classify IXP Traffjc

IXP list

(§4.1) (§4.2) (§4)

VLANs mapping (see Flowchart in §4.2 with the details) AS Relationship Inference Algorithm output

See paper for details

slide-55
SLIDE 55

Spoofer-IX Inference Method:
 Putting the Pieces Together

22

Spoofer-IX method

MAC-to-AS mapping traffjc fmow data

list of networks inferred as with and without SAV, with evidence to support IXP data (§5)

bogon prefjxes unassigned prefjxes routable address space per AS

Address space fundamentals(§2.2)

Prefjx-Level Customer Cone Algorithm Traffjc Classifjcation Pipeline AS-Level Customer Cone Algorithm AS Relationship Inference Algorithm prefjx-to-AS mapping AS relationships inferred siblings ASes IXP validation data to check AS-relationships and prefjxes inferred BGP routing data IANA allocated ASes records

Stage 1: Build the Customer Cone

Route Server data Looking Glass Server data

Stage 2: Classify IXP Traffjc

IXP list

(§4.1) (§4.2) (§4)

VLANs mapping (see Flowchart in §4.2 with the details) AS Relationship Inference Algorithm output

See paper for details

Divided into two stages

slide-56
SLIDE 56

Spoofer-IX Inference Method:
 Putting the Pieces Together

22

Spoofer-IX method

MAC-to-AS mapping traffjc fmow data

list of networks inferred as with and without SAV, with evidence to support IXP data (§5)

bogon prefjxes unassigned prefjxes routable address space per AS

Address space fundamentals(§2.2)

Prefjx-Level Customer Cone Algorithm Traffjc Classifjcation Pipeline AS-Level Customer Cone Algorithm AS Relationship Inference Algorithm prefjx-to-AS mapping AS relationships inferred siblings ASes IXP validation data to check AS-relationships and prefjxes inferred BGP routing data IANA allocated ASes records

Stage 1: Build the Customer Cone

Route Server data Looking Glass Server data

Stage 2: Classify IXP Traffjc

IXP list

(§4.1) (§4.2) (§4)

VLANs mapping (see Flowchart in §4.2 with the details) AS Relationship Inference Algorithm output

See paper for details

Divided into two stages

  • Stage 1: build the Customer Cone
slide-57
SLIDE 57

Spoofer-IX Inference Method:
 Putting the Pieces Together

22

Spoofer-IX method

MAC-to-AS mapping traffjc fmow data

list of networks inferred as with and without SAV, with evidence to support IXP data (§5)

bogon prefjxes unassigned prefjxes routable address space per AS

Address space fundamentals(§2.2)

Prefjx-Level Customer Cone Algorithm Traffjc Classifjcation Pipeline AS-Level Customer Cone Algorithm AS Relationship Inference Algorithm prefjx-to-AS mapping AS relationships inferred siblings ASes IXP validation data to check AS-relationships and prefjxes inferred BGP routing data IANA allocated ASes records

Stage 1: Build the Customer Cone

Route Server data Looking Glass Server data

Stage 2: Classify IXP Traffjc

IXP list

(§4.1) (§4.2) (§4)

VLANs mapping (see Flowchart in §4.2 with the details) AS Relationship Inference Algorithm output

See paper for details

Divided into two stages

  • Stage 1: build the Customer Cone
  • Stage 2: classify IXP traffic
slide-58
SLIDE 58

Stage 1: Build the Customer Cone

23

Full Cone 


(state-of-the-art [1])

Customer Cone


(Prefix-level Customer Cone)

Brief overview in this talk See paper for full details

Subtleties in Cone Construction

Spoofer-IX method MAC-to-AS mapping traffjc fmow data list of networks inferred as with and without SAV, with evidence to support IXP data (§5) bogon prefjxes unassigned prefjxes routable address space per AS Address space fundamentals(§2.2) Prefjx-Level Customer Cone Algorithm Traffjc Classifjcation Pipeline AS-Level Customer Cone Algorithm AS Relationship Inference Algorithm prefjx-to-AS mapping AS relationships inferred siblings ASes IXP validation data to check AS-relationships and prefjxes inferred BGP routing data IANA allocated ASes records Stage 1: Build the Customer Cone Route Server data Looking Glass Server data Stage 2: Classify IXP Traffjc IXP list (§4.1) (§4.2) (§4) VLANs mapping (see Flowchart in §4.2 with the details) AS Relationship Inference Algorithm output
slide-59
SLIDE 59

Stage 1: Build the Customer Cone

23

Full Cone 


(state-of-the-art [1])

Customer Cone


(Prefix-level Customer Cone)

Brief overview in this talk See paper for full details

Subtleties in Cone Construction

Spoofer-IX method MAC-to-AS mapping traffjc fmow data list of networks inferred as with and without SAV, with evidence to support IXP data (§5) bogon prefjxes unassigned prefjxes routable address space per AS Address space fundamentals(§2.2) Prefjx-Level Customer Cone Algorithm Traffjc Classifjcation Pipeline AS-Level Customer Cone Algorithm AS Relationship Inference Algorithm prefjx-to-AS mapping AS relationships inferred siblings ASes IXP validation data to check AS-relationships and prefjxes inferred BGP routing data IANA allocated ASes records Stage 1: Build the Customer Cone Route Server data Looking Glass Server data Stage 2: Classify IXP Traffjc IXP list (§4.1) (§4.2) (§4) VLANs mapping (see Flowchart in §4.2 with the details) AS Relationship Inference Algorithm output

Do not distinguish types of 
 AS-relationships Takes into account the semantics of 
 AS-relationships [2]

slide-60
SLIDE 60

Stage 1: Build the Customer Cone

23

Full Cone 


(state-of-the-art [1])

Customer Cone


(Prefix-level Customer Cone)

Brief overview in this talk See paper for full details

  • More permissive
  • Aims to minimize false positives
  • Acknowledge that intentionally

sacrifices specificity, i.e., inflating the address space considered legitimate

  • Limited input BGP data sanitization

Subtleties in Cone Construction

[1] Lichtblau et al. Detection, Classification, and Analysis

  • f Inter-domain Traffic with Spoofed Source IP Addresses.

In: ACM IMC, 2017.

Spoofer-IX method MAC-to-AS mapping traffjc fmow data list of networks inferred as with and without SAV, with evidence to support IXP data (§5) bogon prefjxes unassigned prefjxes routable address space per AS Address space fundamentals(§2.2) Prefjx-Level Customer Cone Algorithm Traffjc Classifjcation Pipeline AS-Level Customer Cone Algorithm AS Relationship Inference Algorithm prefjx-to-AS mapping AS relationships inferred siblings ASes IXP validation data to check AS-relationships and prefjxes inferred BGP routing data IANA allocated ASes records Stage 1: Build the Customer Cone Route Server data Looking Glass Server data Stage 2: Classify IXP Traffjc IXP list (§4.1) (§4.2) (§4) VLANs mapping (see Flowchart in §4.2 with the details) AS Relationship Inference Algorithm output

Do not distinguish types of 
 AS-relationships Takes into account the semantics of 
 AS-relationships [2]

slide-61
SLIDE 61

Stage 1: Build the Customer Cone

23

Full Cone 


(state-of-the-art [1])

Customer Cone


(Prefix-level Customer Cone)

Brief overview in this talk See paper for full details

  • More permissive
  • Aims to minimize false positives
  • Acknowledge that intentionally

sacrifices specificity, i.e., inflating the address space considered legitimate

  • Limited input BGP data sanitization
  • More restrictive
  • Aims to be accurate
  • Rigorous AS-Path (BGP) sanitization
  • Accounts for hybrid relationships and

accommodates traffic engineering practices

Subtleties in Cone Construction

[1] Lichtblau et al. Detection, Classification, and Analysis

  • f Inter-domain Traffic with Spoofed Source IP Addresses.

In: ACM IMC, 2017. [2] Luckie et al. AS Relationships, Customer Cones, and Validation. In: ACM IMC, 2013.

Spoofer-IX method MAC-to-AS mapping traffjc fmow data list of networks inferred as with and without SAV, with evidence to support IXP data (§5) bogon prefjxes unassigned prefjxes routable address space per AS Address space fundamentals(§2.2) Prefjx-Level Customer Cone Algorithm Traffjc Classifjcation Pipeline AS-Level Customer Cone Algorithm AS Relationship Inference Algorithm prefjx-to-AS mapping AS relationships inferred siblings ASes IXP validation data to check AS-relationships and prefjxes inferred BGP routing data IANA allocated ASes records Stage 1: Build the Customer Cone Route Server data Looking Glass Server data Stage 2: Classify IXP Traffjc IXP list (§4.1) (§4.2) (§4) VLANs mapping (see Flowchart in §4.2 with the details) AS Relationship Inference Algorithm output

Do not distinguish types of 
 AS-relationships Takes into account the semantics of 
 AS-relationships [2]

slide-62
SLIDE 62

Stage 2: Classify IXP Traffic


24

Is SRC AS in Ingress AS's Customer Cone?

Unverifiable Out-of-Cone In-cone

Do we have Mac-to-AS Mapping (ingress, egress) validation ? Given the ingress and egress ASs, is there a verifiable Customer Cone?

No No Yes Yes Yes No source IP + ingress and egress AS + VLANs

Is SRC IP Bogon? Is SRC IP Unassigned?

Bogon No start: for each flow Yes Unassigned Yes source IP only + VLANs No

Phase 1 Phase 2 Phase 3

Spoofer-IX method MAC-to-AS mapping traffjc fmow data list of networks inferred as with and without SAV, with evidence to support IXP data (§5) bogon prefjxes unassigned prefjxes routable address space per AS Address space fundamentals(§2.2) Prefjx-Level Customer Cone Algorithm Traffjc Classifjcation Pipeline AS-Level Customer Cone Algorithm AS Relationship Inference Algorithm prefjx-to-AS mapping AS relationships inferred siblings ASes IXP validation data to check AS-relationships and prefjxes inferred BGP routing data IANA allocated ASes records Stage 1: Build the Customer Cone Route Server data Looking Glass Server data Stage 2: Classify IXP Traffjc IXP list (§4.1) (§4.2) (§4) VLANs mapping (see Flowchart in §4.2 with the details) AS Relationship Inference Algorithm output
slide-63
SLIDE 63

Stage 2: Classify IXP Traffic


24

Is SRC AS in Ingress AS's Customer Cone?

Unverifiable Out-of-Cone In-cone

Do we have Mac-to-AS Mapping (ingress, egress) validation ? Given the ingress and egress ASs, is there a verifiable Customer Cone?

No No Yes Yes Yes No source IP + ingress and egress AS + VLANs

Is SRC IP Bogon? Is SRC IP Unassigned?

Bogon No start: for each flow Yes Unassigned Yes source IP only + VLANs No

Phase 1 Phase 2 Phase 3

Phase 1: filter Bogon and Unassigned addresses

this phase is independent of any routing semantics

Spoofer-IX method MAC-to-AS mapping traffjc fmow data list of networks inferred as with and without SAV, with evidence to support IXP data (§5) bogon prefjxes unassigned prefjxes routable address space per AS Address space fundamentals(§2.2) Prefjx-Level Customer Cone Algorithm Traffjc Classifjcation Pipeline AS-Level Customer Cone Algorithm AS Relationship Inference Algorithm prefjx-to-AS mapping AS relationships inferred siblings ASes IXP validation data to check AS-relationships and prefjxes inferred BGP routing data IANA allocated ASes records Stage 1: Build the Customer Cone Route Server data Looking Glass Server data Stage 2: Classify IXP Traffjc IXP list (§4.1) (§4.2) (§4) VLANs mapping (see Flowchart in §4.2 with the details) AS Relationship Inference Algorithm output
slide-64
SLIDE 64

Stage 2: Classify IXP Traffic


25

Is SRC AS in Ingress AS's Customer Cone?

Unverifiable Out-of-Cone In-cone

Do we have Mac-to-AS Mapping (ingress, egress) validation ? Given the ingress and egress ASs, is there a verifiable Customer Cone?

No No Yes Yes Yes No source IP + ingress and egress AS + VLANs

Is SRC IP Bogon? Is SRC IP Unassigned?

Bogon No start: for each flow Yes Unassigned Yes source IP only + VLANs No

Phase 1 Phase 2 Phase 3

Phase 2: filter Unverifiable packets

packets that are not suitable to inference of spoofing using the inferred cones

  • r due to IXP topology and traffic visibility impediments
Spoofer-IX method MAC-to-AS mapping traffjc fmow data list of networks inferred as with and without SAV, with evidence to support IXP data (§5) bogon prefjxes unassigned prefjxes routable address space per AS Address space fundamentals(§2.2) Prefjx-Level Customer Cone Algorithm Traffjc Classifjcation Pipeline AS-Level Customer Cone Algorithm AS Relationship Inference Algorithm prefjx-to-AS mapping AS relationships inferred siblings ASes IXP validation data to check AS-relationships and prefjxes inferred BGP routing data IANA allocated ASes records Stage 1: Build the Customer Cone Route Server data Looking Glass Server data Stage 2: Classify IXP Traffjc IXP list (§4.1) (§4.2) (§4) VLANs mapping (see Flowchart in §4.2 with the details) AS Relationship Inference Algorithm output
slide-65
SLIDE 65

Stage 2: Classify IXP Traffic


26

Is SRC AS in Ingress AS's Customer Cone?

Unverifiable Out-of-Cone In-cone

Do we have Mac-to-AS Mapping (ingress, egress) validation ? Given the ingress and egress ASs, is there a verifiable Customer Cone?

No No Yes Yes Yes No source IP + ingress and egress AS + VLANs

Is SRC IP Bogon? Is SRC IP Unassigned?

Bogon No start: for each flow Yes Unassigned Yes source IP only + VLANs No

Phase 1 Phase 2 Phase 3

Phase 3: classify Packets with Customer Cone

packets whose source IP belongs to the sending AS’s customer cone address space are classified as in-cone. Otherwise, we classify the packet as out-of-cone

Spoofer-IX method MAC-to-AS mapping traffjc fmow data list of networks inferred as with and without SAV, with evidence to support IXP data (§5) bogon prefjxes unassigned prefjxes routable address space per AS Address space fundamentals(§2.2) Prefjx-Level Customer Cone Algorithm Traffjc Classifjcation Pipeline AS-Level Customer Cone Algorithm AS Relationship Inference Algorithm prefjx-to-AS mapping AS relationships inferred siblings ASes IXP validation data to check AS-relationships and prefjxes inferred BGP routing data IANA allocated ASes records Stage 1: Build the Customer Cone Route Server data Looking Glass Server data Stage 2: Classify IXP Traffjc IXP list (§4.1) (§4.2) (§4) VLANs mapping (see Flowchart in §4.2 with the details) AS Relationship Inference Algorithm output
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SLIDE 66

Longitudinal Study

  • Study realized at the third largest IXP 


at the Brazilian IX.br ecosystem

  • Transports up to 200 Gbps of traffic 


among 200+ members

  • Two uninterrupted sFlow datasets:
  • April 1 to May 6, 2017 (5 weeks)
  • May 1 to June 5, 2019 (5 weeks)
  • sampling rate 1/4096
  • Compare our method with Full Cone (state-
  • f-the-art) [1]

27 Blue box: IXPs Iocations.

Brazilian IX.br ecosystem 
 [IX.br, 2019]

[1] Lichtblau et al. Detection, Classification, and Analysis of Inter-domain Traffic with Spoofed Source IP Addresses. In: ACM IMC, 2017.

slide-67
SLIDE 67

What Have We Found ?

  • No strong evidence of pervasive presence of spoofed traffic for the

different observation periods in 2017 and 2019


  • Found an upper bound volume of out-of-cone traffic to be more than an
  • rder of magnitude less than the state-of-the-art method
  • Our method reveals inaccuracies in methods that are agnostic to 


AS-relationship semantics

28

Brief overview See paper for details

slide-68
SLIDE 68

Longitudinal Traffic Classification

29

Apr 1 - May 6, 2017 May 1 - Jun 5, 2019

(i) In-cone (ii) Unverifiable (iv) Bogon (iii) Out-of-cone

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SLIDE 69

Longitudinal Traffic Classification

29

Apr 1 - May 6, 2017 May 1 - Jun 5, 2019

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SLIDE 70

Longitudinal Traffic Classification

29

Apr 1 - May 6, 2017 May 1 - Jun 5, 2019

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SLIDE 71

Longitudinal Traffic Classification

29

Apr 1 - May 6, 2017 May 1 - Jun 5, 2019

15.3% of total traffic exchanged at the IXP

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SLIDE 72

Longitudinal Traffic Classification

29

Apr 1 - May 6, 2017 May 1 - Jun 5, 2019

84.65% of the traffic classified as In-cone

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SLIDE 73

Longitudinal Traffic Classification

29

Apr 1 - May 6, 2017 May 1 - Jun 5, 2019

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SLIDE 74

Comparison of Out-of-cone Traffic Inferred by Each Method

30

(a) Spoofer-IX (b) State-of-the-art

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SLIDE 75

Comparison of Out-of-cone Traffic Inferred by Each Method

30

(a) Spoofer-IX (b) State-of-the-art

Spoofer-IX inferred a peak

  • f 40 Mbps
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SLIDE 76

Comparison of Out-of-cone Traffic Inferred by Each Method

30

(a) Spoofer-IX (b) State-of-the-art

Full Cone method inferred a peak of 2.5 Gbps Spoofer-IX inferred a peak

  • f 40 Mbps
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SLIDE 77

Comparison of Out-of-cone Traffic Inferred by Each Method

31

(b) State-of-the-art

Traffic Volume (Gbps) 0.5 1 transport 1.5 2 2.5 3 01 May 02 May 03 May 04 May 05 May 06 May 07 May 08

  • ther

May p2c−outofcone

Unverifiable traffic

92.6% was sent from a provider to a customer across the exchange — 
 where no cone of valid addresses applies

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SLIDE 78

Comparison of Out-of-cone Traffic Inferred by Each Method

32

activity and churn in active IP addresses

(b) State-of-the-art (a) Spoofer-IX

slide-79
SLIDE 79

Comparison of Out-of-cone Traffic Inferred by Each Method

33

spatio-temporal properties in active IP addresses

(b) State-of-the-art (a) Spoofer-IX

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SLIDE 80

Comparison of Out-of-cone Traffic Inferred by Each Method

34

None of the metrics results correlated with a typical attack pattern

(b) State-of-the-art (a) Spoofer-IX

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SLIDE 81

Takeaways

  • Few efforts have tried to empirically measure SAV compliance for

networks attached to the global Internet

  • We have exposed fundamental challenges and developed a new

method to classify traffic flows

  • We hope that our work be used to further improve our collective

ability to measure and expand deployment of SAV filtering

35

slide-82
SLIDE 82

Takeaways

  • Few efforts have tried to empirically measure SAV compliance for

networks attached to the global Internet

  • We have exposed fundamental challenges and developed a new

method to classify traffic flows

  • We hope that our work be used to further improve our collective

ability to measure and expand deployment of SAV filtering

35

Lucas Müller lfmuller@inf.ufrgs.br

Thank you!
 Questions?