Riverstone Networks WICT1-12 - Manual (Page 287)

Riverstone Networks RS Switch Router User Guide Release 8.0 16-29
BGP Configuration Guide BGP Configuration Examples
16.3.5 Local Preference Examples
There are two methods of specifying the local preference with the
bgp set peer-group
command:
• Setting the
local-pref
option. This option can only be used for the internal, routing, and IGP
group types and is not designed to be sent outside of the AS.
• Setting the
set-pref
option, which allows the RS IP routing code (ROSRD) to set the local
preference to reflect ROSRD’s own internal preference for the route, as given by the global protocol
preference value. Note that in this case, local preference is a function of the ROSRD preference and
set-pref options.
Figure 16-7 shows a BGP configuration that uses the BGP local preference attribute in a sample BGP configuration
with two autonomous systems. All traffic exits Autonomous System 64901 through the link between router R13 and
router R11. This is accomplished by configuring a higher local preference on router R13 than on router S12. Because
local preference is exchanged between the routers within the AS, all traffic from AS 64901 is sent to R13 as the exit
point.