Forwarding-loop-free configuration for IBGP networks

Abstract

We investigate the inter-cluster routing deflection and forwarding loops in IBGP networks. In more detail, we define and explore the two causes of deflection, and consecutively, forwarding loops which might happen due to IBGP cluster misconfiguration. We study the methods that can be used to remove forwarding loops, if detected. Unfortunately, we show that detecting forwarding loops in a given IBGP network configuration is NP-hard. However, we propose a simple heuristic algorithm with complexity of 0(2) to configure deflection- and loop-free IBGP network.