.. _example_protocols_bgp_parameters_disable-network-import-check:

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Disable-Network-Import-Check
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Scenario to verify BGP **disable-network-import-check** parameter configuration.

By default, BGP performs an IGP route check for networks configured via the ``network``
command. This means BGP will only advertise a network if it exists in the RIB (Routing
Information Base) - learned from IGP protocols, static routes, or connected interfaces.
This prevents accidentally advertising unreachable destinations. Routes that fail this
validation appear in the BGP table with the "=" symbol but without "*" (valid) or ">"
(best) markers, indicating they are present but not usable for advertisement.

The ``disable-network-import-check`` parameter disables this safety check, allowing BGP
to advertise networks regardless of their presence in the RIB. This is useful when
advertising aggregate routes, blackhole routes for traffic filtering, or in scenarios
where network existence checking is handled by other mechanisms. This implements the
"no-install" pattern where aggregates are announced externally but not installed locally.

In this test, **DUT0** (AS 100) advertises an aggregate network ``192.168.0.0/16`` via
BGP. In the first phase, a static route exists and the network is marked as valid and best
in the BGP table, so it is advertised successfully. In the second phase, the static route
is removed and BGP stops advertising the network because it no longer exists in the RIB.
In the third phase, after enabling ``disable-network-import-check``, BGP advertises the
network to **DUT1** (AS 200) again even without a RIB entry, demonstrating the "no-install"
aggregate pattern.

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Test BGP Disable Network Import Check
*************************************

Description
===========

This test demonstrates the effect of ``disable-network-import-check`` on BGP network
advertisement for aggregate routes. **DUT0** (AS 100) is configured to advertise an
aggregate network ``192.168.0.0/16``. The test follows three phases: first, a static
blackhole route exists and BGP advertises the aggregate successfully. Second, the static
route is removed and BGP stops advertising it due to default import-check validation.
Finally, ``disable-network-import-check`` is enabled, allowing BGP to advertise the
aggregate to **DUT1** (AS 200) even though it doesn't exist in the RIB. This demonstrates
the common "no-install" pattern for aggregate route advertisement.

Scenario
========

.. include:: disable-network-import-check/testbgpdisablenetworkimportcheck

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