Virtual Private Routed Network Services
7750 SR OS Services Guide Page 1097
A route can be learned by the router from different protocols in which case the costs are not 
comparable, when this occurs the preference is used to decide to which route will be used.
Different protocols should not be configured with the same preference, if this occurs the tiebreaker is 
per the default preference table as defined in  Table 7. If multiple routes are learned with an identical 
preference using the same protocol, the lowest cost route is used. 
If multiple routes are learned with an identical preference using the same protocol and the costs 
(metrics) are equal, then the decision of what route to use is determined by the configuration of the 
ecmp in the config>router context.
The no form of the command reverts to the default value.
Default preference 10 — OSPF internal routes have a preference of 10.
Parameters preference — The preference for internal routes expressed as a decimal integer. Defaults for different 
route types are listed in Table 7. 
 
Values 1 — 255
reference-bandwidth 
Syntax reference-bandwidth reference-bandwidth
no reference-bandwidth 
Context config>service>vprn>ospf
Description This command configures the reference bandwidth in kilobits per second (Kbps) that provides the 
reference for the default costing of interfaces based on their underlying link speed. 
Table 7: Route Preference Defaults by Route Type 
Route Type Preference Configurable
Direct attached 0 No 
Static routes 5 Yes
OSPF internal 10
Yes
a
a. Preference for OSPF internal routes is configured with the preference 
command.
IS-IS level 1 internal 15 Yes
IS-IS level 2 internal 18 Yes
RIP 100 Yes
OSPF external 150 Yes
IS-IS level 1 external 160 Yes
IS-IS level 2 external 165 Yes
BGP 170 Yes