1. OverviewΒΆ
The following diagram depicts a fairly common use case where a border router provides connectivity to the Internet via several Peering and Transit Service Providers.
The outside network connectivity via eBGP provides service availability using different ASes. The inside network connectivity is established using an IGP (Internal Gateway Protocol) that usually relies on OSPF or iBGP or a combination of both. In the described case and for illustration purposes, we will be using iBGP and OSPFv2.
To avoid the border router being a single point of failure, we will describe how an ISP can provide a multi-homed BGP peering with several peering and transit providers.
The setup we will be implementing in the following guide will be structured as follows:
