Title
Route flap damping exacerbates internet routing convergence
Abstract
Route flap damping is considered to be a widely deployed mechanism in core routers that limits the widespread propagation of unstable BGP routing information. Originally designed to suppress route changes caused by link flaps, flap damping attempts to distinguish persistently unstable routes from routes that occasionally fail. It is considered to be a major contributor to the stability of the Internet routing system.We show in this paper that, surprisingly, route flap damping can significantly exacerbate the convergence times of relatively stable routes. For example, a route to a prefix that is withdrawn exactly once and re-announced can be suppressed for up to an hour (using the current RIPE recommended damping parameters). We show that such abnormal behavior fundamentally arises from the interaction of flap damping with BGP path exploration during route withdrawal. We study this interaction using a simple analytical model and understand the impact of various BGP parameters on its occurrence using simulations. Finally, we outline a preliminary proposal to modify route flap damping scheme that removes the undesired interaction in all the topologies we studied. .
Year
DOI
Venue
2002
10.1145/633025.633047
Special Interest Group on Data Communication
Keywords
Field
DocType
route withdrawal,route change,link flap,stable route,various bgp parameter,persistently unstable route,undesired interaction,unstable bgp routing information,bgp path exploration,route flap,bgp,internet routing,border gateway protocol
Default-free zone,Dynamic Source Routing,Static routing,Computer science,Computer security,Computer network,Border Gateway Protocol,Source routing,Routing Information Protocol,Route poisoning,Routing protocol
Conference
Volume
Issue
ISSN
32
4
0146-4833
ISBN
Citations 
PageRank 
1-58113-570-X
120
10.88
References 
Authors
12
4
Search Limit
100120
Name
Order
Citations
PageRank
Zhuoqing Morley Mao15719363.11
ramesh govindan2154302144.86
George Varghese38149727.66
Randy H. Katz4168193018.89