Configuring gated
Specifying Route Preference
Specifying Route Preference
gated maintains a routing table that consists of the route information learned from OSPF and from other active routing protocols, such as RIP or EGP. You can also configure static routes in the /etc/gated.conf file with one or more static clauses (see “Installing Static Routes” on page 90 for more information).
The gated routing pool can therefore contain multiple routes to a single destination. When multiple routes exist, the route chosen by gated is determined by the following (in order of precedence):
•The preference value associated with the route. The preference value is a number in the range from 0 (most preferred) to 255 (least preferred). Routes from different sources have different default preference values. For example, OSPF routes within a given AS have a preference value of 10. Table
•If multiple routes use the same protocol and have the same preference value, the route with the lowest metric or cost is chosen.
•If metric or cost is the same, the router with the lowest IP address is chosen.
Table | Default Preference Values of Routes | ||
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| Route Type | Preference | /etc/gated.config Configuration |
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| Interface | 0 | Can be changed with interface |
| routes |
| statement in Interface class. |
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| OSPF inter- | 10 | Cannot be changed. |
| and |
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| Internal | 20 | Generated by BGP or EGP when |
| default |
| routing information is learned from |
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| a peer. |
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| ICMP Redirect | 30 | Can be changed with redirect |
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| statement in Protocol class. |
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| SNMP | 50 | Can be changed in SNMP statement in |
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| Protocol class. |
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94 | Chapter 3 |
