Network Router User Manual

Chapter 12: BGP Configuration Guide
154 SmartSwitch Router User Reference Manual
Using the local-pref Option
For router SSR12’s CLI configuration file, local-pref is set to 194:
For router SSR13, local-pref is set to 204.
Using the set-pref Option
The formula used to compute the local preference is as follows:
Local_Pref = 254 – (global protocol preference for this route) + set-pref metric
Note:
A value greater than 254 will be reset to 254. GateD will only send Local_Pref
values between 0 and 254.
In a mixed GateD and non-GateD network, the non-GateD IBGP implementation may
send Local_Pref values that are greater than 254. When operating a mixed network of this
type, you should make sure that all routers are restricted to sending Local_Pref values in
the range metric to 254.
In router SSR12’s CLI configuration file, the import preference is set to 160:
Using the formula for local preference [Local_Pref = 254 - (global protocol preference for
this route) + metric], the Local_Pref value put out by router SSR12 is 254 - 160+100 = 194.
For router SSR13, the import preference is set to 150. The Local_Pref value put out by
router SSR13 is 254 - 150+100 = 204.
Note the following when using the set-pref option:
• All routers in the same network that are running GateD and participating in IBGP
should use the set-pref option, and the set-pref metric should be set to the same value.
bgp set peer-group as901 local-pref 194
bgp set peer-group as901 local-pref 204
#
# Set the set-pref metric for the IBGP peer group
#
bgp set peer-group as901 set-pref 100
ip-router policy create bgp-import-source as900 autonomous-system 64900
preference 160
ip-router policy create bgp-import-source as900 autonomous-system 64900
preference 150