Presentation given by Mark Dranse in February 2009

1. RIPE Network Coordination Centre
APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse 1
Observations on the anycast root
using DNSMON
Mark Dranse
RIPE NCC Information Services
markd@ripe.net
http://is-portal.ripe.net

2. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
2
What is DNSMON anyway?
• Infrastructure DNS Monitoring
• Probes from ~80 globally distributed probes
• Monitors root, .arpa, ENUM, ccTLD, gTLD
Active
Pending

3. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
3
Methodology

4. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
4
Root server locations?

5. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
5
Root server locations
http://www.root-servers.org

6. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
Anycast instance view
6

7. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
7
Anycast instance reporting

8. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
Total number of anycast servers seen
8
0
10
20
30
40
50
60
70
80
90
100
A B C D E F G H I J K L M
Sites Instances
167 sites
383 servers detected
...
168 Verisign
84 ICANN
(66% combined)

9. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
Anycast implementations
9
root Sites Servers
A
B
C
D
E
F
G
H
I
J
K
L
M
2 > 30
1 3
6 2
1 1
1 4
46 1
1 2
1 3
31 1-2
52 > 2
17 2
2 42
6 4
0
10
20
30
40
50
0 10 20 30 40 50 60
Servers
Sites
A B
C D
E F
G H
I J
K L
M

10. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
10
k2.amsix from one probe, 9 weeks

11. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
11
Probes seeing k1.amsix
24 Hours
14 Days7 Days
48 Hours
9
13 15
12

12. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
12
Server - k1.amsix - 2 weeks
PT
IE
US
BR
RU
CY
CZ
DE
LU
NL
NL
NL

13. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
Probes seen over time
13
0
6
12
18
24hr 48hr 1week 2week
A C E F I J K L M

14. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
14
Instances seen per probe*
1
2
3
4
5
6
7
8
9
10
11
12
0% 35% 70%
I root
1
2
3
4
5
6
7
8
9
10
11
12
0% 35% 70%
1
2
3
4
5
6
7
8
9
10
11
12
0% 35% 70%
J root K root
* Sample of 69 probes, 2 week period

15. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
Load balancing - J
15

16. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
More load balancing
16
• G1 seen by all probes
• Similar to J, but fewer nodes
• k1.nap - clients focus

17. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
Conclusions
• Anycast DNS very stable
- Due to high redundancy
• Most operators have few sites, few servers
- 2 have few sites, many servers
- 4 have many sites, few servers
- Mix of static/dynamic load balancing
• Measurement probes fairly stable
- Some strange routing going on
- Temporary flaps observed due to local (probe) network
17

18. APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse
RIPE Network Coordination Centre
Obligatory IPv6 slide
• 8 enabled, 5 not enabled
• 127 sites operated by these 8 IPv6 enabled roots
• 38 of 127 sites IPv6 enabled (30%)
18
root Total
sites
v6 Sites % IPv6 IPv4
Servers
Visible IPv4
servers
Visible IPv6
servers
A
B
F
H
J
K
L
M
2 2 100% > 30 74 4
1 1 100% 3 3 0
46 17 40% 1 46 12
1 1 100% 3 3 1
52 2 4% > 2 94 4
17 8 53% 2 23 11
2 2 100% 42 84 4
6 5 83% 4 15 10

19. RIPE Network Coordination Centre
APNIC27 - Manila - February 2009 http://www.ripe.netMark Dranse 19
Questions?