Fault-Tolerant Reconfigurable Ethernet-Based IP Network Proxy

摘要

Using commonly available hardware and software, we present a proxy scheme for IP over Ethernet networks that provides a fault-tolerant solution without the need for modification of existing networking equipment. This type of fault-tolerant reconfigurable Ethernet-based proxy (FREP) is transparent to current applications and provides full redundancy with minimal packet loss and fast reconfiguration times. A prototype implementation yielded a reconfiguration time of 1.55 sec. Routing delays from the OSPF dynamic routing protocol, however, increased the apparent interruption of service to an average of 10.2 sec when tested in a three-subnet/three-router testbed network. An almost instantaneous recovery time of < 0.02 sec was observed in all cases. The proposed proxy scheme can be deployed in any network based on a topology that allows two connections between a subnet and the backbone. The solution relies on a dynamic routing protocol to provide backbone-level routing around the malfunctioning inter-network link.