Topology discovery for large ethernet networks
Proceedings of the 2001 conference on Applications, technologies, architectures, and protocols for computer communications
Automatic VLAN creation based on on-line measurement
ACM SIGCOMM Computer Communication Review
Simple network performance tomography
Proceedings of the 3rd ACM SIGCOMM conference on Internet measurement
Topology discovery in heterogeneous IP networks: the NetInventory system
IEEE/ACM Transactions on Networking (TON)
Shrink: a tool for failure diagnosis in IP networks
Proceedings of the 2005 ACM SIGCOMM workshop on Mining network data
IP fault localization via risk modeling
NSDI'05 Proceedings of the 2nd conference on Symposium on Networked Systems Design & Implementation - Volume 2
Towards highly reliable enterprise network services via inference of multi-level dependencies
Proceedings of the 2007 conference on Applications, technologies, architectures, and protocols for computer communications
Characterizing VLAN usage in an operational network
Proceedings of the 2007 SIGCOMM workshop on Internet network management
NetDiagnoser: troubleshooting network unreachabilities using end-to-end probes and routing data
CoNEXT '07 Proceedings of the 2007 ACM CoNEXT conference
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Many enterprise, campus, and data-center networks have complex layer-2 virtual LANs ("VLANs") below the IP layer. The interaction between layer-2 and IP topologies in these VLANs introduces hidden dependencies between IP level network and the physical infrastructure that has implications for network management tasks such as planning for capacity or reliability, and for fault diagnosis. This paper characterizes the extent and effect of these dependencies in a large campus network. We first present the design and implementation of EtherTrace, a tool that we make publicly available, which infers the layer-2 topology using data passively collected from Ethernet switches. Using this tool, we infer the layer-2 topology for a large campus network and compare it with the IP topology. We find that almost 70% of layer-2 edges are shared by 10 or more IP edges, and a single layer-2 edge may be shared by as many as 34 different IP edges. This sharing of layer-2 edges and switches among IP paths commonly results from trunking multiple VLANs to the same access router, or from colocation of academic departments that share layer-2 infrastructure, but have logically separate IP subnet and routers. We examine how this sharing affects the accuracy and specificity of fault diagnosis. For example, applying network tomography to the IP topology to diagnose failures caused by layer-2 devices results in only 54% accuracy, compared to 100% accuracy when our tomography algorithm takes input across layers.