Configuring an Overload Bit for an IPv4 IS-IS Device

If an IS-IS device needs to be temporarily isolated, configure the overload state for it to prevent other devices from forwarding traffic to this IS-IS device and prevent routing black holes.

Context

If an IS-IS device needs to be temporarily isolated, for upgrade or maintenance purposes for example, configure the overload state for it so that no other devices will forward traffic to this IS-IS device.

IS-IS routes converge more quickly than BGP routes do. To prevent routing black holes on a network where both IS-IS and BGP are configured, set an overload bit to instruct an IS-IS device to enter the overload state during its start or restart. After BGP convergence is complete, cancel the overload bit.

Procedure

  1. Run system-view

    The system view is displayed.

  2. Run isis [ process-id ]

    The IS-IS view is displayed.

  3. Run set-overload { on-startup [ timeout1 | start-from-nbr system-id [ timeout1 [ timeout2 ] ] | wait-for-bgp [ timeout1 ] ] [ route-delay-distribute timeout4 ] [ send-sa-bit [ timeout3 ] ] [ route-max-metric ] } [ allow { interlevel | external } * ]

    The overload bit is configured.

  4. Run commit

    The configuration is committed.

Copyright © Huawei Technologies Co., Ltd.
Copyright © Huawei Technologies Co., Ltd.
< Previous topic Next topic >