1. Visualization of Temporal Difference of BGP Routing Information
Ryo SAKIYAMA Koji OKAMURA Youngseok LEE
Graduate School
of Information Science
and Electrical Engineering,
Kyushu University
Computing and
Communications Center,
Kyushu University
Dept. of Computer Science
and Engineering, Faculty of
Electrical and Computer
Engineering,
Chungnam National University
My name is Ryo Sakiyama, I'm student of graduate school
of Information Science and Electrical Engineering, Kyushu University in Japan.
The presantation title is “Visualization of Temporal Difference of BGP Routing Information”
2019/4/20

2. Contents Background Purpose Research Conclusion Routing Information
How to visualize
Introducing ABEL2
Example Analysis
Future Works
Conclusion
2019/4/20

3. Background (1/2)
AS (Autonomous System) is a set of routers under a single technical administration.
There are two kinds of routing protocols:
Intra-AS routing protocol : IGP (Interior Gateway Protocol)
Inter-AS routing protocol : EGP (Exterior Gateway Protocol)
BGP (border Gateway Protocol) always selects the stable routes.
AS 3
BGP
BGP
BGP
BGP
BGP
Router
AS 1
AS 2
2019/4/20

4. Background (2/2)
BGP is used to exchange routing information for the Internet.
When the network failures occur, the alternative routes are selected dynamically according to the BGP routing policy.
These policies are usually very complex because there are a lot of ASes.
AS 3
AS 4
AS 3
AS 4
AS 2
AS 2
AS 6
AS 7
AS 6
AS 7
AS 1
AS 1
Normal Route
Route at network failure
2019/4/20

5. Purpose
Network operators design the alternative routing policy as the backup route.
Understand that what alternative route
is selected according to BGP routing policy.
Changes of routes could be easily understood with a graphical visualization tool of BGP routing tables.
Develop a visualization tool of Temporal Difference of BGP Routing Information
2019/4/20

6. Related Work CAIDA (Cooperative Associate for Internet Data Analysis)
Visualization of IPv4 Internet
Each AS is plotted as a point in the circle, and ASes are connected with lines.
Core ASes at the center of the network are important, because the global connectiviy could be lost.
Too complex to understand the changes of route.
Emphasize the changes of route
with a simple BGP routing table visualization tool.
2019/4/20

7. Routing Information 2497 7018 80 3.0.0.0 BGP Routing Information
Recorded at AS 2523 (QGPOP)．
Saved at a file hard every ten minutes.
Path
Network
Routing tables
9270
APAN KR
List of ASes which relay packets to the destination AS in order.
We can analyze relationship between target AS and other ASes.
Network Next Hop Metric LocPrf Weight Path
*>i i
*>i i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / I
*>i / i …
7660
APAN JP
2523
QGPOP
2907
SINET …
2497
IIJ
2508
Kyushu-u
2500
WIDE
2019/4/20

8. Problems of Visualization
It is difficult for Network operators to understand that alternative route is selected from BGP routing tables.
Routing tables are large-scale data.
Networks:180,000
ASes: 20,000
File Size: 15MB
Network Next Hop Metric LocPrf Weight Path
*>i i
*>i i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / i
*>i / I … ？ ？
Example of Routing Table
2019/4/20

9. How to Visualize
Visualization of the entire Internet is very complex to understand the changes of routes.
Especially pay attention are changes of routes.
Suggest a graphical tool that present only the change of routes to network operators.
AS 10
AS 11
AS 3
AS 4
AS 3
AS 4
AS 5
AS 2
AS 2
AS 6
AS 7
AS 6
AS 7
AS 1
AS 8
AS 1
AS 9
Observation
Observation
Visualization of the whole BGP routing tables
Visualization of the Changes of routes
2019/4/20

10. ABEL2
Named ABEL2 that visualize the routing information for temporal route changes tool.
ABEL2 (A routing recording database system based on Bgp for nEtwork management and appLication software version 2).
JAVA was used for visualization.
ABEL2 consists of two stages for visualization.
Convert routing information into data suitable for efficient visualization.
Visualize the changes of routes.
2019/4/20

11. Calculate Changes of routes
Record the BGP routing table every ten minutes.
Calculate the difference between two BGP routing tables every ten minutes.
2006/07/01 10:00
2006/07/01 10:10
Network … Path
/ …
/ …
/24 …
/23 … …
Network … Path
/ …
/ …
/23 …
/22 … …
Changes of routes
Date Time Network AS From To
2006/07/01 10: /
2006/07/01 10: / none
2006/07/01 10: / none
2019/4/20

12. Weights by Prefix Length (1/3)
ABEL2 puts weights on the prefix length in BGP routing information.
Influence of the route change can be reflected.
Based on IP address Classes (Class A, Class B, and Class C).
The edge width denotes the weight of prefix length.
Network Path
x.x.x.x/24 AS 1 AS 2 AS 3 AS 4
y.y.y.y/23 AS 1 AS 2 AS 3 AS 5 AS 6
z.z.z.z/22 AS 1 AS 2 AS 7 AS 8
AS 4
Prefix Length: 24 > Class C : 1
AS 3
x.x.x.x/24
AS 1
AS 2
AS 5
AS 6
Prefix Length: 23 > Class C : 2
y.y.y.y/23
AS 7
AS 8
Prefix Length: 22 > Class C : 4
z.z.z.z/22
2019/4/20

13. Weights by Prefix Length (2/3)
Search for the routes connected between ASes from the routing table.
Calculate the number of Class A, Class B or Class C for every route.
Routing Table
Network … Path
/ …
/ …
/24 …
/24 …
/23 …
/22 …
/22 … …
AS AS 7018, Class A: 1
AS AS 80, Class A: 1
AS AS 3356, Class A: 1
AS AS 701, Class C: 2
AS AS , Class C: 2
AS AS 6496 , Class C: 2
2019/4/20

14. Weights by Prefix Length (3/3)
Compare two files that have calculated routing tables.
if the number of Class A, Class B or Class C for each route changes, it is thought that the route was changed．
0:00
0:10
Connection Prefix Length
A:1, B:2, C:0
A:0, B:1, C:5
A:0, B:0, C:5 …
Connection Prefix Length
10429 – A:1, B:1, C:0
A:0, B:1, C:5
A:0, B:0, C:6 …
Weights by Prefix Length
Time Changed Connection Prefix Length Variation
00: A:1, B:2, C:0 A:0, B:-1, C:0
00: A:0, B:0, C:6 A:0, B:0, C:+1 …
2019/4/20

15. Visualization
Connections between ASes in the graph are displayed such that ASes are denoted by nodes and the routes by edges.
The node/link layout algorithm is simple.
The AS must not overlap with other ASes.
The distance between ASes are constant.
The edge width denotes the weight of prefix length．
Changes of routes
11456
Time Network AS From To
00: / …
-A:1
10429
Weights by Prefix Length
+A:1
Time Connection Prefix Length Variation
00: A:1, B:0, C:0 A:-1, B:0, C:0
00: A:0, B:0, C:0 A:+1, B:0, C:0 …
-A:1
17238
22818
Observation
2019/4/20

16. Visualization Example of Visualization
country-by-country different color.
Deleted Connections
AS Number
AS Name
Country
Added Connection
2019/4/20

17. About ABEL2 http://saki.ok.csce.kyushu-u.ac.jp/abel/
Number of added path
Time
Information of
selected AS
Number of Deleted path
2019/4/20

18. Example Analysis (1/3) Number of changed Paths January 9, 2006.
It is observed that the peak of route
changes was around 8:20 AM.
Changed Paths
Number of Paths
Deleted Paths
Added Paths
Time
2019/4/20

19. Example Analysis (2/3) 2006/01/09 8:20 ISP in Germany 13237
LAMBDANET-AS
Hannover, Germany
2019/4/20

20. Example Analysis (3/3) Route Flapping
Observe the phenomenon that the same route changes frequently in a day.
January 9, 2006.
20:30
20:40
5:30
2:30
0:00
1:40
2:20
From AS To AS 12302
2019/4/20

21. Future works
Make a module of generating statistics on the long-term route changes.
Since ABEL2 presents the route changes that are calculated from the differences between two routing tables.
ABEL2 will be more useful with the analysis of route changes regarding either route flapping or network failure.
2019/4/20

22. Conclusion Suggest the visualization tool
Help network operators understand that alternative route is selected according to BGP routing policy.
Visualized the route changes by analyzing of routing tables which are being regularly saved to files.
Have developed a graphical tool, ABEL2, that can present the route changes.
We believe ABEL2 will be useful for network operators to design the alternative routing policies for the backup route.
2019/4/20

23. Thank You!
2019/4/20