Tier 0 Router Does Not Advertise Learned /32s To Tier 1

Products

• VMware NSX

Issue/Introduction

• Routes from BGP and/or OSPF are learned on the T0.
• The connected T1 router does not have these routes available, even if they are more specific than the connected segments on the T1.

Environment

• VMware NSX

Cause

T0 and T1 routers do not use a routing protocol between them.  The T1 is auto-plumbed with information from the segments and creates a default path to the T0.

Routes from a T1 are not advertised to a T0 via a routing protocol.  They are a function of the management plane in NSX.  T0 routes are not advertised to a T1, T1 has an auto-generated default route to the T0 and connected routes for the adjacent (east/west) segments.

Resolution

For more information on architecture and routing expectations, please see the reference design guide, section 4.2 (page 94) in the NSX reference design guide.