Scaling Bgp - Enterasys Security Router X-PeditionTM User Manual

Overview

Scaling BGP

BGP requires that all BGP speakers with a single AS (IBGP) be fully meshed, as shown in
10. The result is that for any BGP speakers within an AS, the number of unique BGP sessions
required is determined by the following formula: n x (n-1)/2. Be aware that this fully meshed
requirement does not scale when a large number of IBGP speakers occupy the AS.
As an example, when an AS contains five routers as shown above, the number of BGP sessions
needed is 10, as set by the equation: 5 x (5-1)/2 = 10.
6-18 Configuring the Border Gateway Protocol
Figure 6-10 Fully Meshed BGP
Figure 6-