Advanced VPRN Topologies and Services
Glenn Warnock B.Sc., Mira Ghafary B.Sc., Ghassan Shaheen M.Sc. · 2015
This chapter describes the various loop prevention techniques that can be used in a VPRN to allow a CE to accept BGP routes originated in remote VPN sites configured with the CE's AS number. It covers different VPRN topologies including full mesh, hub and spoke, and extranet. The chapter examines three approaches that can be used to provide Internet access to CEs: Internet access using the global route table, Internet access using route leaking between VRF and the global route table, and Internet access using an extranet VPRN with an Internet VRF. It explains techniques that modify the BGP update so that the CE accepts routes originated in a remote site configured with the same AS number. The VPRN topology configured for a customer is dictated by its business requirements. The chapter describes the commonly used topologies and illustrates their implementation in the Alcatel-Lucent Service Router Operating System (SR OS).