一种快速收敛的热土豆路由算法
A Fast-Convergence Routing of the Hot-Potato
摘要：
域内和域间路由协议之间的相互作用很少受到关注，尽管在转发中转流量方面发挥了重要作用。更准确地说，默认情况下，BGP会考虑IGP距离来为中转流量选择最近的出口网关（热土豆路由）。在IGP更新时，新的最佳网关可能会改变，并且应该通过BGP的（完全）重新收敛来更新，这在许多情况下会导致多余的BGP处理和更新。我们提出了OPTIC（最佳保护技术的域间-域内收敛），一个有效的方法来组装这两个协议，而不会失去烫手山芋属性。OPTIC预先计算由前缀组共享的网关集（BGP下一跳）。这样的集合保证在分组前缀的任何单个IGP事件之后包含融合后网关。新的最佳出口可以通过每个集合的单个走查来找到，从而允许传输流量几乎在IGP收敛时就从最佳BGP路由中受益。与vanilla BGP相比，OPTIC的结构允许它考虑减少的条目数量：对于存根网络，这个数量可以减少99%。OPTIC结构的更新（只要边界路由器保持至少双向连接就不需要）随其组数的时间线性缩放。
英文摘要：
Interactions between the intra- and inter-domain routing protocols received little attention despite playing an important role in forwarding transit traffic. More precisely, by default, IGP distances are taken into account by BGP to select the closest exit gateway for the transit traffic (hot-potato routing). Upon an IGP update, the new best gateway may change and should be updated through the (full) re-convergence of BGP, causing superfluous BGP processing and updates in many cases. We propose OPTIC (Optimal Protection Technique for Inter-intra domain Convergence), an efficient way to assemble both protocols without losing the hot-potato property. OPTIC pre-computes sets of gateways (BGP next-hops) shared by groups of prefixes. Such sets are guaranteed to contain the post-convergence gateway after any single IGP event for the grouped prefixes. The new optimal exits can be found through a single walk-through of each set, allowing the transit traffic to benefit from optimal BGP routes almost as soon as the IGP converges. Compared to vanilla BGP, OPTIC's structures allow it to consider a reduced number of entries: this number can be reduced by 99\% for stub networks. The update of OPTIC's structures, which is not required as long as border routers remain at least bi-connected, scales linearly in time with its number of groups.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
