Patent ID: 6473421
Filing Date: 2002-10-29
Classification: H04L

Abstract:
An OSPF domain configured as a plurality of OSPF areas and comprising a plurality of OSPF-speaking label-switching routers, including at least one area border router and one autonomous-system border router, that maintain forwarding information bases containing forwarding entries, identified by respective forwarding labels, that contain information that the label-switching routers use for forwarding packets toward respective destinations, at least some of the label-switching routers responding to reception of an AS-External LSA by interpreting part of the AS-External LSA's External Route Tag field as indicating whether the External Route Tag field contains a forwarding label and, if so, interpreting part of the External Route Tag field as a forwarding label and installing that forwarding label as a replacement label in any forwarding entry based on that LSA for the destination that the AS-External LSA's Link-State ID field specifies.