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======Case 9. Creating a Custom Local AS======

Cubro SG periodically updates public ASN databases. A custom AS is used when it is necessary to isolate a portion of IP addresses from a public AS for the purpose of obtaining statistics or prioritizing by direction.\\ 
In this section, it is possible to create a custom local AS and override the IP addresses that belong to the public AS into this local AS.

  - Navigate to the section //AS & DSCP → Add AS//\\ {{:csg:use_case:img_1.png?direct&250|}}
  - Create a local AS. Fill in the fields: 
    * AS Number
    * AS Name
    * Description\\ {{:csg:use_case:img_2.png?direct&600|}}
  - Specify resources for overriding. IP addresses or prefixes can be imported either through the clipboard (Import Resources button) or through files (Import from File button).\\ The list format: One column: IPv4 / IPv6 / IPv4-prefix / IPv6-prefix. The column specifies the IP address or prefix.\\ If an IPv4 address is specified, a subnet mask of /32 will be added;\\ If an IPv6 address is specified, a subnet mask of /128 will be added;\\ Supported file formats include: CSV, TSV, XLSX, TXT. The XLSX format is converted to CSV on-the-fly.
  - Save the rule by clicking the “Save” or “Save and Disable” button\\ {{:csg:use_case:img_3.png?direct&1000|}}

The rule applies to all traffic and to all channels and subscribers.

All overridden ASs are displayed in the section //AS & DSCP → AS resource list//. Filtering and searching can be performed based on the list of blocks and resources. [[csg:use_case:blacklists:rules_and_resources_list|Learn more about searching]]\\ {{:csg:use_case:img_4.png?direct&1200|}}