Default Route Preference Values
The Junos OS routing protocol process assigns a default preference value to each route that the routing table receives. The default value depends on the source of the route. The preference value is a value from 0 through 4,294,967,295 (232 – 1), with a lower value indicating a more preferred route. Table 1 lists the default preference values.
Table 1: Default Route Preference Values
How Route Is Learned | Default Preference | Statement to Modify Default Preference |
|---|---|---|
Directly connected network | 0 | – |
System routes | 4 | – |
Static and Static LSPs | 5 | |
RSVP-signaled LSPs | 7 | RSVP preference as described in the Junos MPLS Applications Configuration Guide |
LDP-signaled LSPs | 9 | LDP preference, as described in the Junos MPLS Applications Configuration Guide |
OSPF internal route | 10 | OSPF preference |
IS-IS Level 1 internal route | 15 | IS-IS preference |
IS-IS Level 2 internal route | 18 | IS-IS , preference |
Redirects | 30 | – |
Kernel | 40 | – |
SNMP | 50 | – |
Router discovery | 55 | – |
RIP | 100 | RIP preference |
RIPng | 100 | RIPng preference |
PIM | 105 | Junos Multicast Protocols Configuration Guide |
DVMRP | 110 | Junos Multicast Protocols Configuration Guide |
Aggregate | 130 | |
OSPF AS external routes | 150 | OSPF external-preference |
IS-IS Level 1 external route | 160 | IS-IS external-preference |
IS-IS Level 2 external route | 165 | IS-IS external-preference |
BGP | 170 | BGP preference, export, import |
MSDP | 175 | Junos Multicast Protocols Configuration Guide |
In general, the narrower the scope of the statement, the higher precedence its preference value is given, but the smaller the set of routes it affects. To modify the default preference value for routes learned by routing protocols, you generally apply routing policy when configuring the individual routing protocols. You also can modify some preferences with other configuration statements, which are indicated in the table. For information about defining and applying routing policies, see the Junos Policy Framework Configuration Guide.
