Managing Transit Traffic with the Overload Bit

If a router lacks the resources to maintain a complete link state database, routing packets to it could result in a blackhole or routing loop. The overload bit prevents this undesirable behavior by indicating to the other routers that the afflicted router should not be used as a transit router. Packets destined for directly attached routes can still be routed to a router with the overload bit set, but all other routing paths reconverge around it.

To manually enable the overload bit feature, use the following command:
enable isis area area_name overload-bit {suppress [external | interlevel | all]}
To configure the router to automatically set the overload bit on startup, use the following command:
configure isis area area_name overload-bit on-startup [ off | {suppress [external | interlevel | all]} seconds]
To disable the overload bit feature, use the following command:
disable isis area area_name overload-bit

Note

Enabling or disabling the overload bit feature does not modify the configuration of the command:

configure isis area area_name overload-bit on-startup [ off | {suppress [external | interlevel | all]} seconds]

Published March 2020prev | next

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