Design Reference

Table Of Contents
Figure 29: Multiple regions separated by EBGP
You can obtain AS numbers from the Inter-Network Information Center (NIC) or use private
AS numbers. If you use private AS numbers, be sure to design your Internet connectivity
carefully. For example, you can introduce a central, well-known AS to provide interconnections
between all private ASs and the Internet. Before it propagates the BGP updates, this central
AS strips the private AS numbers to prevent them from leaking to providers.
The following figure illustrates a design scenario in which you use multiple OSPF regions to
peer with the Internet.
Figure 30: Multiple OSPF regions peering with the Internet
Border Gateway Protocol
Network Design Reference for Avaya VSP 4000 February 2014 71