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”Operational stability of the Internet ” SANOG1 - Kathmandu, Nepal 2003-01-25 Kurtis Lindqvist.

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Presentation on theme: "”Operational stability of the Internet ” SANOG1 - Kathmandu, Nepal 2003-01-25 Kurtis Lindqvist."— Presentation transcript:


2 ”Operational stability of the Internet ” SANOG1 - Kathmandu, Nepal Kurtis Lindqvist

3 Sida 1 © Netnod AB Slides available at

4 Sida 2 © Netnod AB Who is Netnod? Continuation of D-GIX Established in 1997 Operates four exchanges in Sweden –Stockholm, Gothenburg, Malmö, Sundsvall Have been the first (only) exchange point to use DPT/SRP/RPR/ –Switching to Gigabit Ethernet

5 Sida 3 © Netnod AB The Internet has changed

6 Sida 4 © Netnod AB Different needs Medical applications on STM-1 based IP- VPNs On-line banking applications Production dependent IP-VPNs VoIP Down-time is starting to have an effect

7 Sida 5 © Netnod AB The Internet of today won’t do it IGP convergence Will impact your service offering –IP-VPNs –VoIP services –Banking? Not really new… …and relatively easy to fix

8 Sida 6 © Netnod AB The Internet of today won’t do it IGP convergence –Can be improved with IGP timers for both ISIS and OSPF

9 Sida 7 © Netnod AB The Internet of today won’t do it IGP convergence Suggestions to fix the protocol also exists –See Cengiz Alaettinoglu presentation at the ISIS-WG in San Diego Dec 2000 But also be done at Layer 2…

10 Sida 8 © Netnod AB The Internet of today won’t do it BGP Convergence Convergence is poor as documented by Abha Ahuja and Craig Labovitz Will also impact your service offering –How do I do intra-provider VoIP?

11 Sida 9 © Netnod AB The Internet of today won’t do it BGP convergence Harder to fix –Problem with the protocol A number of suggestions are out there –Dampening might harm you, see Randy Bush et al at RIPE in Rhodes and last Nanog For a long term fix we need to find a better way of doing this…

12 Sida 10 © Netnod AB we still need to do Interconnects…

13 Sida 11 © Netnod AB Interconnections Transit connections Direct peerings Exchange points

14 Sida 12 © Netnod AB Transit connections ”Where the rest goes” –Your way to the most of the Internet Often protected so that you won’t get isolated in case of failures Critical as otherwise you will be an isolated island of the Internet

15 Sida 13 © Netnod AB Direct peerings Direct links between two ISPs Normally redundant –For economical ”fairness” Not really crucial as you can send traffic through the upstream –But might be crucial depending on your traffic ratio

16 Sida 14 © Netnod AB Exchange points Many ISPs connected to common and shared media Normally limited protection Limited effect if lost –But can still force large volume of traffic to be shifted and leading to higher cost

17 Sida 15 © Netnod AB What if we loose an exchange point? Tested in full scale at Netnod Migration of mountain cave

18 Sida 16 © Netnod AB Netnod is running a number of exchangepoint medias Cisco DPT / SRP –622 Mbps –2.5Gbps FDDI –Legacy Gigabit Ethernet –Bridged to FDDI

19 Sida 17 © Netnod AB Netnod setup - GigE 1 Customer router Extreme switches FDDI Switches AB

20 Sida 18 © Netnod AB Netnod setup - GigE 2 Customer routers Extreme switches FDDI Switches AB

21 Sida 19 © Netnod AB Netnod setup - DPT

22 Sida 20 © Netnod AB …and then we migrated ”A”… …so what happened? Nothing really…

23 Sida 21 © Netnod AB Government project Study of the overall stability of the Internet in Sweden –DNS –Exchange points Gathered a number of data –BGP logs of 10 ISPs…almost –BGP listening on US East/west coast –Load graphs

24 Sida 22 © Netnod AB Traffic shifted as planned

25 Sida 23 © Netnod AB No real BGP activity - withdrawals

26 Sida 24 © Netnod AB No real BGP activity - Advertisement

27 Sida 25 © Netnod AB BGP Activity - details

28 Sida 26 © Netnod AB What conclusions can we make? Exchange points are not really crucial –Some ISPs actually shifted the traffic beforehand Interconnects can be made stable –Layer 2 convergence will help –But GigE can also be made to work… –…but you need to be careful

29 Sida 27 © Netnod AB So what do we think happened? Well, the only thing that really changed was the NEXT_HOP Backup paths was known So BGP recalculation was very limited, if at all But this needs planning and luck! –And not necessarily in that order…

30 Sida 28 © Netnod AB Operational stability All this is examples of how to improve operational stability But why do I needed it? –The answer is obvious Or is it? –How dependent is your country on the Internet?

31 Sida 29 © Netnod AB Operational stability Netnod was to some extent created out of the needs for stable Internet in Sweden –The physical exchange is located in caves owned by the government –But they have no control over it Gov and we where concerned about physical security –As far as I know unique - which have proved to be useful

32 Sida 30 © Netnod AB Operational stability Physical security is the easy part –Todays attacks are logical The Swedish government is moving into CERT like functions and is trying to find their role –The idea is good –But they add little value to the solution of the real problem –Still they are needed and can be useful –Early start is goood

33 Sida 31 © Netnod AB Operational stability The challenge in the future lies in moving forward on two fronts –Physical –Logical Both are well understood… …but poorly implemented

34 Sida 32 © Netnod AB Conclusions Operational stability is becoming more and more crucial –For revenue and infrastructure Work with your goverment before they work with you There is a lot you can do (should have done) to increase the stability of your network –And the rest of the Internet Conferences like these are good!

35 Sida 33 © Netnod AB Go do it! Before you wake up and is forced to!

36 Sida 34 © Netnod AB ?

37 Sida 35 © Netnod AB Contact Netnod Internet Exchange i Sverige AB Bellmansgatan 30 I SE Stockholm Sweden Office address: Bellmansgatan 30 I Telephone: Telefax: URL: http//

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