Topology Discovery Using an Address Prefix Stopping Rule

1
Topology Discovery Using an Address Prefix
Stopping Rule

• Benoit Donnet
• Joint work with Timur Friedman
• Eunice 2005 Madrid (Spain)

2
Context

• Network measurement
• Internet topology discovery using distributed
  traceroute monitors
• IP interface level
• Existing tools
• Skitter (CAIDA)
• TTM (RIPE NCC)
• AMP (NLANR)
• DIMES (Tel Aviv U.)

3
Scaling Problem

• More monitors means more load on
• network resources
• destinations
• Classical approaches either
• stay small (skitter, TTM, AMP)
• trace slowly (DIMES)
• Can we trace more efficiently?

4
Contributions

• Efficient cooperative topology discovery
  algorithm
• Doubletree (Sigmetrics2005)
• Load on destinations and communication cost
  reduction
• probing stopping rule based on CIDR address
  prefixes

5
Doubletree - Basics

• Cooperative algorithm
• Goal avoiding paths already explored
• Exploit tree-like structure of routes in the
  internet
• from a monitor to a set of destinations
• Backward probing (first suggested by Govindan et
  al.)
• from a set of monitors to a destination
• Forward probing and monitor coordination

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Doubletree Monitor-rooted tree
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Doubletree Destination-rooted tree
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Doubletree Probing scheme

• Two probing schemes
• Backwards
• Forwards
• Stop sets (interface, root)
• Local Stop Set B interface
• Global Stop Set F (interface, destination)
• shared by monitors
• Doubletree starts probing at some hop h from the
  monitor

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Limitations

• Load on destination
• Potentially, all the destinations may be hit by
  monitors
• Communication cost
• Global stop set exchange needs too high network
  resources
• Up to 20.6MB for only 50,000 destinations

10
Destination-based stopping rule
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Solution

• Destination addresses aggregation through the use
  of CIDR prefixes
• Global stop set of (interface,
  prefix_destination

12
Solution (2)
13
Results (1)
14
Results (2)
15
Results (3)
16
Results (4)
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Conclusion

• Improvements to Doubletree
• Load on destinations reduced
• Communication cost reduced
• Future works
• Implementation
• BGP-guided topology discovery
• Clustering