# Autonomous System Numbers

An Autonomous System (AS) is a group of one or more IP prefixes (lists of IP addresses accessible on a network) run by
one or more network operators that maintain a single, clearly defined routing policy. Network operators need
Autonomous System Numbers (ASNs) to control routing within their networks and to exchange routing information with
other Internet Service Providers (ISPs). [Reference](https://www.arin.net/resources/guide/asn/).

NetSPI manually identifies ASNs by searching for your (and your subsidiaries') legal names in our
[ASN data provider](https://ipinfo.io/products/asn-api) and associating them with your attack surface. IP addresses
for all discovered ASNs are automatically added to your attack surface.

## Accessing the ASN Page

Use the following steps to access the ASN page.

1. Select the top menu Assets -> EASM Assets to display the Assets page with focus on the EASM Assets tab.
2. Then select ASN to display all the ASNs discovered that are associated with your organization.

![EASM ASN table](/static/easm/asm_asn_table.png "EASM ASN table")

Here you can:

- Search ASN information using the search field or [filter ASNs](#filter-asn-assets) by selecting the
filter icon ![Filter Icon](/static/filter_icon.png) above the table.
- Customize the table columns that display by selecting the column
icon ![Table Column Icon](/static/table_column_icon.png) to
[configure column data](/general-navigation/search-sort-and-filter-tables/#configure-column-heading-display)
- Select check boxes for a row or group of rows and take the following bulk actions by selecting
the **Bulk Actions** button:
  - Export selected ASN assets in a [CSV format](/general-navigation/managing-table-records/#bulk-actions-drop-down-menu)
  - Add or remove monitoring

![ASN Bulk Actions](/static/easm/asn_bulk_actions.png "ASN Bulk Actions")

## Filter ASN assets

On the ASN page, select any filter criteria from the
[filter drop-down](/general-navigation/search-sort-and-filter-tables/#apply-a-new-filter) list to view the ASNs
of interest.

!!!
See [Filtering assets](/EASM/assets/#filtering-assets) for instructions on customizing the table view and the
[Save applied filter as a preset](/general-navigation/search-sort-and-filter-tables/#save-applied-filters-as-a-preset)
to save your user-defined filters for reuse.
!!!

You can also select any of the ASN metrics cards to apply a filter to the table below that matches that metric criteria.

![ASN metrics cards](/static/easm/asn_stats.png "ASN metrics cards")

## Viewing ASN details

1. Select any ASN table row to display the ASN details page and view the risk score, related open findings and tags.

   ![ASN Details](/static/easm/asm_asn_details.png "ASN Details")

   Select the full-page icon ![Full page view](/static/easm/full_page_view_icon.png) in the ASN
   table row to view it in full-page view. You can select this icon in the right panel details view to expand
   it to full-page view as well.

   ![ASN Account Details full page](/static/easm/asn_details_full_page.png "ASN Account Details full page")

2. Select the ASN details view tabs to view the overview, findings, engagements, activity, and comments.

## Adding an asset

See [Adding an asset](/EASM/assets/#adding-an-asset) for instructions on adding an asset.