D. Chang, R. Govindan, and J. Heidemann, "An Empirical Study of Router Response to Large BGP Routing Table Load", Tech. Rep. ISI-TR-2001-552, USC/Information Sciences Institute, December 2001.
|An Empirical Study of Router Response to Large BGP Routing Table Load|
|Published:||USC/Information Sciences Institute, 2001|
|Abstract:||Anecdotal evidence suggests that misconfiguration of backbone routers occasionally leads to an injection of large routing tables into the BGP routing system. In this paper, we investigate the detailed mechanics of router response to large BGP routing tables. We examine three commercial routers, and find that their responses vary significantly. Some routers exhibit table-size oscillations that have the potential to cause cascading failure. Others need operator intervention to recover from large routing tables. We also find that deployed resource control mechanisms, such as prefix limits and route flap damping, are only partially successful in mitigating the impact of large routing tables.|
|Experiments:||Three different commercial BGP routers were placed in simple topologies. The behaviour of individual routers under large router load was measured. In addition, the effect on other routers in the topology was measured. The routers measured were Cisco 7000 (IOS 11.1), Cisco 12008 GSR (IOS 12.0) and Juniper M20 (JUNOS 4.3 and 4.4).|
The authors pose the following question:
How do routers from different vendors behave when confronted with routing table loads that exceed their capacity?
Their findings are:
Finally, the authors list a number of goals for designing a graceful failure mode of a BGP router.