Overview

Scaling BGP

BGP requires that all BGP speakers with a single AS (IBGP) be fully meshed, as shown in Figure 6- 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.

Figure 6-10 Fully Meshed BGP

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

Page 166
Image 166
Enterasys Networks X-PeditionTM manual Scaling BGP, Fully Meshed BGP