1. computer networks research group @ roma III university inter-domain routing, ipv6, and network visualization giuseppe di battista maurizio patrignani

2. computer networks research group @ roma III university - namex 19 nov 04 main research topics interdomain routing –analysis of the route changes for the incoming traffic flows –location of the internet routing instabilities –modeling of bgp configurations and analysis of their stability –inference of the customer-provider relationships –study of the routing (a)symmetries –engineering of the incoming traffic flows –discovery of a large(r) as graph –integration and visualization of the irr info intradomain routing –ospf visualization –layer-3 discovery techniques ipv6 –support for the ipv4-ipv6 transition –multi-homing methods network emulation –cheap and easy-to-configure test-beds for complex networks

3. computer networks research group @ roma III university - namex 19 nov 04 analysis of the route changes for the incoming traffic flows development of a web service, called bgplay, visualizing the route changes of a prefix in a specific time window two running servers at –routing information service of the ripe ncc (www.ris.ripe.net/bgplay/) –route views project of the oregon university (www.routeviews.org) each based on the corresponding repository of bgp updates an alpha version at roma III university with the most recent features

4. computer networks research group @ roma III university - namex 19 nov 04 bgplay query form specify the prefix (network) you want to monitor specify an interval of time select data sources

5. computer networks research group @ roma III university - namex 19 nov 04

6. bgplay demo

7. computer networks research group @ roma III university - namex 19 nov 04 location of the internet routing instabilities monitoring of the network from several vantage points –each vantage point stores the bgp updates that are “visible” from its location related updates are grouped into “events” the causes of each event are (if possible) identified by studying the evolution of the routing over time

8. computer networks research group @ roma III university - namex 19 nov 04 modeling of bgp configurations and analysis of their stability study of formal models for the description of bgp configurations and behaviors study of the effect of different time sequences of the events identification of possible routing instabilities routing stability vs forwarding stability –stability of the entire routing information base vs stability of the best choice

9. computer networks research group @ roma III university - namex 19 nov 04 inference of the customer-provider relationships a simple model accounting for customer- provider and peer-to-peer relationships only infer the types of relationship between autonomous systems by observing the as-paths associated with announcements –if sensible rules of thumb are followed by network operators, each as-path is “valley free” if rules of thumb are followed by network operators, relationships can be efficiently inferred

10. computer networks research group @ roma III university - namex 19 nov 04 inference of the customer-provider relationships if a set of relationships making all as-paths valley free does not exist –we prove that maximizing the number of valley free as-paths is a hard problem –we propose heuristics for this problem that outperform cutting-edge techniques described in literature

11. computer networks research group @ roma III university - namex 19 nov 04 study of the routing (a)symmetries netviewer web service –prototype at www.dia.uniroma3.it/~compunet/ having at disposal internal and external info shows routing asymmetries group prefixes into classes that have the same routing in cooperation with caspur and garr

12. computer networks research group @ roma III university - namex 19 nov 04 example of routing classes 198.150.84.0 198.150.85.0 198.150.87.0 198.150.2.0 198.150.22.0 198.150.38.0 198.150.4.0 198.150.5.0 198.150.6.0 198.150.7.0 198.150.9.0 1 st July 2003

13. computer networks research group @ roma III university - namex 19 nov 04 example of asymmetric routing 1 st July 2003 = 129.125.0.0/16 = 130.136.0.0/16

14. computer networks research group @ roma III university - namex 19 nov 04 engineering of the incoming traffic flows even a limited control of the announcements propagation could be used to –balance traffic from the upstream providers –prefer reliable incoming paths –improve internal traffic flows engineering incoming traffic via prepending –Integer Linear Programming formulation –computational geometry perspective

15. computer networks research group @ roma III university - namex 19 nov 04 discovery of a large(r) AS graph starting from the bgp updates collected by the ris or orv repositories a big picture of the internet can be obtained this picture can be enlarged by observing “unusual” bgp traffic –bgp updates with peculiar timings –bgp updates with peculiar content we can gain extra info by –observing unusual bgp updates –probing the network with unusual bgp updates for example setting up suitable beacons and observing echoes in cooperation with namex

16. computer networks research group @ roma III university - namex 19 nov 04 integration and visualization of the irr info hermes service –available at www.dia.uniroma3.it/~hermes/ handles a local relational database of routing information –downloads rpsl information from more than 50 databases that are individually operated by organizations such as verio, cable & wireless, merit, ripe ncc, apnic, arin, sprint, etc. through a java applet it is possible to navigate the repository and obtain information about the rpsl objects

17. computer networks research group @ roma III university - namex 19 nov 04 integration and visualization of the irr info

18. computer networks research group @ roma III university - namex 19 nov 04 integration and visualization of the irr info

19. computer networks research group @ roma III university - namex 19 nov 04 integration and visualization of the irr info

20. computer networks research group @ roma III university - namex 19 nov 04 integration and visualization of the irr info

21. computer networks research group @ roma III university - namex 19 nov 04 integration and visualization of the irr info

22. computer networks research group @ roma III university - namex 19 nov 04 integration and visualization of the irr info

23. computer networks research group @ roma III university - namex 19 nov 04 ospf visualization polyphemous tool –downloadable from www.dia.uniroma3.it/~polyph/ collects routing information using snmp and mibs explores an ospf network at different levels of abstraction –shows ospf areas an area border routers –shows routers and links inside each area –provides detailed info about areas, routers, interfaces. in cooperation with caspur

24. computer networks research group @ roma III university - namex 19 nov 04 ospf visualization

25. computer networks research group @ roma III university - namex 19 nov 04 layer-3 discovery techniques nethunter service –available at www.dia.uniroma3.it/~nethunt/ exploits a collection of traceroute servers explores the surroundings of an ip interface or network by performing traceroutes from different vantage points uses a logic engine for inferring topologies –guess and check approach to asses whether two interfaces belong to the same router

26. computer networks research group @ roma III university - namex 19 nov 04 support for the ipv4-ipv6 transition techniques to detect, and collect information about, ipv6- in-ipv4 tunnels (mtu-discovery, dns, ip spoofing,…) discovered tunnels can be used as “vantage points” to launch third-party tunnel-discovery explorations, scaling up the discovery process wide experimentation –6bone tunneled network, garr network, wide network, ripe ncc network and ttm test-boxes we assess to what extent 6bone registry information is coherent with the actual network topology we provide the first experimental results on the current distribution of ipv6-in-ipv4 tunnels in the Internet in cooperation with garr and ripe ncc

27. computer networks research group @ roma III university - namex 19 nov 04 multi-homing methods hosts in a multi-homed as receive an ipv6 address from each upstream provider how to handle multiple ipv6 addresses? –need to take into account traffic loads –need to propagate information from the border routers to the internal networks –need to swap ipv6 addresses without dropping tcp connections

28. computer networks research group @ roma III university - namex 19 nov 04 cheap and easy-to-configure test- beds for complex networks netkit (network emulator) –available at www.netkit.org a linux kernel may run as a user process (user mode linux) a network of linux virtual machines may run on a single host each linux may be configured to run routing daemons (zebra, bird, gated, routed, xorp, quagga,…) new configurations may be tested before being deployed in cooperation with garr

29. computer networks research group @ roma III university - namex 19 nov 04 concluding remarks a mixed theoretical-technical approach in all topics tight relationships with network operators –caspur, garr, namex, orv, ripe, … research-teaching coupling –univ. courses on comp. networks and courses on specific technologies for companies and pa

30. computer networks research group @ roma III university - namex 19 nov 04 thank you! questions?