INL: IP Networking Lab - Internet

IGen: Generation of Router-level Internet Topologies through Network Design Heuristics

bqu — Fri, 29 May 2009 07:43:00 +0000

Network researchers often need to evaluate newly proposed algorithms and protocols over realistic topologies. Many researchers use random networks for such evaluations. Unfortunately, random networks do not accurately model real networks and important parameters such as link metrics or iBGP configurations are often ignored. We propose IGen, a freely available topology generator that uses network design heuristics to generate realistic IP network topologies. We explain the objectives of IGen and describe the topology generation process in details.

Preventing the Unnecessary Propagation of BGP Withdraws

vvandens — Tue, 10 Mar 2009 14:23:49 +0000

Due to the way BGP paths are distributed over iBGP sessions inside an
Autonomous System (AS), a BGP withdraw that follows a failure may be propa-
gated outside the AS although other routers of the AS know a valid alternate path.
This causes transient losses of connectivity and contributes to the propagation of
a large number of unnecessary BGP messages. In this paper, we show, based on
RouteViews data, that a signiﬁcant number of BGP withdraws are propagated
even though alternate paths exists in another border router of the same AS.