How can an OSPF route be hidden so that it is not advertised to any other area

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A filter list cannot solve this problem. You solve this problem through the following methods:

Configure route summarization on the Area Border Router (ABR), specifying the no-advertise keyword in the route summarization command.
Configure the filtering of OSPF ABR Type-3 LSAs. This feature extends the ABR capabilities so that an ABR can filter routes when advertising Type-3 LSAs between OSPF areas. This feature allows only packets with specified prefixes to be sent from one area to another area and restricts all packets with other prefixes. This type of area filtering can be applied out of a specific OSPF area, into a specific OSPF area, or into and out of the same OSPF areas at the same time.

Other related questions:
How does an S series switch hide an OSPF route so that the route is not advertised to any other area
Question: How to hide an OSPF route so that it is not advertised to any other area? Answer: A filter list on an S series switch supporting OSPF cannot prevent a route from being advertised. You can use either of the following methods: Configure route summarization on an ABR and specify the keyword no-advertise in the command. Configure an ABR to filter the routes carried in Type 3 LSAs. The ABR filters routes when advertising Type 3 LSAs between OSPF areas. Only the packets with prefixes meeting requirements can be transmitted from one area to another. In this way, the incoming and outgoing packets of an area are controlled.

How to configure the U1900 so that users in different office areas cannot communicate with each other?
Discriminate prefixes of different area numbers. Specifically, specify 32-level customized rights for different area number prefixes And then configure corresponding customized rights for numbers in corresponding areas.

Configuring OSPF to import default routes on the USG2000 series
Configure OSPF to import default routes on the USG2000 series as follows: 1. In the user view, run the system-view command to enter the system view. 2. Run the ospf [ process-id ] command to access the OSPF view. 3. Select the following configurations as required. To import a default route to the OSPF process, run the default-route-advertise [ [ always | permit ] | cost cost | type type | route-policy route-policy-name ] * command. To specify the default cost of Type-3 summary LSA, run the default-route-advertise summary cost cost command.

Configuring OSPF to import default routes on the USG6000 series
Configure OSPF to import default routes on the USG6000 series as follows: 1. In the user view, run the system-view command to enter the system view. 2. Run the ospf [ process-id ] command to access the OSPF view. 3. Select the following configurations as required. To import a default route to the OSPF process, run the default-route-advertise [ [ always | permit ] | cost cost | type type | route-policy route-policy-name ] * command. To specify the default cost of Type-3 summary LSA, run the default-route-advertise summary cost cost command.

Can an S series switch correctly calculate routes when OSPF backbone areas are not continuous
For S series switches supporting OSPF, if OSPF backbone areas are not continuous, some areas may be unreachable and loops may occur on inter-area and external routes.

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