When multiple routes are configured to a destination, all next-hop routes are maintained and it is necessary to keep track of the state of each route to determine which routes are preferred, offline, or alternate. There are four different route states as follows.
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Route State |
Description |
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|---|---|---|---|
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ACTIVE |
This route is currently being used for network communication and has open dialogs associated with it. For IPv4 networks, ACTIVE routes cannot be deleted or aged from the routing table unless forced with the NOW attribute.
For IPv6 networks, the ACTIVE state only implies that the route is usable; the route can be deleted from the routing table without using the NOW attribute. |
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IDLE |
This route is currently available for use and provides access to the specified destination. There are no open dialogs associated with it at this time. IDLE routes can be deleted and, if not statically configured, aged from the routing table. |
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INACTIVE |
This route has been configured to be an alternate or backup route to the specified destination by having a higher preference value than another primary route to the same destination. Routes can also become INACTIVE when redirected by the network due to changes in the topology or inaccurate static configuration. INACTIVE routes have access to their destinations but are not generally the preferred path. INACTIVE routes can be deleted and, if not statically configured, aged from the routing table. |
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OFF-LINE |
This route cannot be used. Dynamic mechanisms within TCP/IP and the network have determined that the next-hop router is “off-line." The OFF-LINE status might only be temporary and can change as network topology conditions change. Depending on the configuration, another route might now be servicing the dialogs originally assigned to this route. OFF-LINE routes can be deleted and, if not statically configured, aged from the routing table. |
