just a quick question concerning the bgp synchronization. Why was synchronisation ever created ? ie in view of the IGP having to know the route ( in a transit AS) for connectivity to be maintained (bgp being distributed into the IGP thus uable to support a full internet table)
I can understand that too. What I seem confused with is why would any one design or have a transit AS with an IGP involved in the first place knowing the constraints of IGP's handling an internet route table to avoid blackholing?