Configuring An Overload Bit For An Ipv4 Is-Is Device - Huawei Quidway NetEngine80E Configuration Manual

HUAWEI NetEngine80E/40E Router
Configuration Guide - IP Routing
l Based on the IP prefix: filter-policy ip-prefix ip-prefix-name import
l Based on the Route-Policy: filter-policy route-policy route-policy-name import
----End

7.4.5 Configuring an Overload Bit for an IPv4 IS-IS Device

If an IS-IS device needs to be temporarily isolated, configure the IS-IS device to enter the
overload state to prevent other devices from forwarding traffic to this IS-IS device and prevent
blackhole routes.
Context
If an IS (for example, an IS to be upgraded or maintained) needs to be temporarily isolated,
configure the IS to enter the overload state so that no device will forward traffic to this IS.
IS-IS routes converge more quickly than BGP routes. To prevent blackhole routes on a network
where both IS-IS and BGP are configured, set an overload bit to instruct an IS to enter the
overload state during its start or restart. After BGP convergence is complete, cancel the overload
bit.
Procedure
Step 1 Run:
system-view
The system view is displayed.
Step 2 Run:
isis [ process-id ]
The IS-IS view is displayed.
Step 3 Run:
set-overload [ on-startup [ timeout1 | start-from-nbr system-id [ timeout1
[ timeout2 ] ] | wait-for-bgp [ timeout1 ] ] [ send-sa-bit [ timeout3 ] ] ]
[ allow { interlevel | external }
The overload bit is configured.
----End
7.4.6 Configuring IS-IS to Generate IPv4 Default Routes
This section describes how to configure Intermediate System to Intermediate System (IS-IS) to
generate default routes to control the advertising of IS-IS routing information.
Context
The destination address and mask of a default route are all 0s. If the destination address of a
packet does not match any entry in the routing table of a device, the device sends the packet
Issue 02 (2014-09-30)
Route filtering using a whitelist: Configure a rule with a smaller number and specify
the action permit in this rule to permit the routes to be received or advertised by the
system. Then, configure another rule with a larger number in the same ACL and
specify the action deny in this rule to filter out unwanted routes.
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
*
]
7 IS-IS Configuration
533