ROUTE vs. INETNUM: What’s the Story?

The distinction between ROUTE and INETNUM objects is critical in understanding how CIDRs are managed and associated with ASNs. These are database objects used by RIRs to track IP address allocations and routing information.

INETNUM Object

• Definition: An INETNUM (Internet Number) object represents an allocated or assigned range of IP addresses (a CIDR or IP range) managed by an RIR or delegated to an organization (e.g., ISP, end-user).
• Purpose:
  • Tracks the allocation or assignment of an IP address range.
  • Records administrative details, such as the organization holding the IP range, contact information, and status (e.g., allocated, assigned).
  • Indicates who owns or manages the IP range, not necessarily how it’s routed.
• Scope: Primarily administrative. It’s about IP address ownership or stewardship, not routing.
• Key Attributes (in RIPE, for example):
  • inetnum: The IP range (e.g., 203.0.113.0 - 203.0.113.255 or 203.0.113.0/24).
  • netname: A descriptive name for the network.
  • status: Allocation status (e.g., ALLOCATED, ASSIGNED).
  • org: The organization responsible for the range.
  • admin-c/tech-c: Contact details.
• ASN Association: An INETNUM object does not directly specify an ASN. It’s about allocation, not routing. However, the organization listed may also control an ASN, or the CIDR may be referenced in a ROUTE object for routing purposes.
• Example:

inetnum: 203.0.113.0 - 203.0.113.255  
  netname: EXAMPLE-NET  
  org: ORG-EX1-RIPE  
  status: ASSIGNED  
  admin-c: EX1-RIPE  
  tech-c: EX1-RIPE

ROUTE Object

• Definition: A ROUTE object represents a CIDR (or IP range) that is announced in the global BGP routing table by a specific ASN.
• Purpose:
  • Tracks the routing of an IP prefix, specifying which ASN is responsible for announcing it to the internet.
  • Helps ensure that only authorized ASNs announce a given CIDR, preventing route hijacking.
  • Used by network operators to validate BGP announcements.
• Scope: Routing-focused. It’s about how the CIDR is advertised on the internet.
• Key Attributes (in RIPE, for example):
  • route: The CIDR being announced (e.g., 203.0.113.0/24).
  • origin: The ASN announcing the route (e.g., AS12345).
  • descr: Description of the route.
  • mnt-by: Maintainer responsible for the object.
• ASN Association: The ROUTE object directly specifies the ASN via the origin attribute, explicitly linking the CIDR to the autonomous system announcing it.
• Example:

route: 203.0.113.0/24  
  origin: AS12345  
  descr: Example Network Route  
  mnt-by: EXAMPLE-MNT

Key Differences Between INETNUM and ROUTE

Relationship Between INETNUM and ROUTE

• Complementary Roles:

  • An INETNUM object defines the allocation of a CIDR (who it’s assigned to).
  • A ROUTE object defines how that CIDR is routed (which ASN announces it).

• Overlap:

  • A CIDR in an INETNUM object may have a corresponding ROUTE object if it’s publicly routable. For example, 203.0.113.0/24 might be allocated to an ISP in an INETNUM and announced by that ISP’s ASN in a ROUTE object.
  • Not all INETNUM CIDRs have ROUTE objects. For example, private IPs or non-routed allocations (e.g., for internal use) won’t have ROUTE objects.

• Sub-Allocations:

  • An INETNUM might cover a large block (e.g., 203.0.112.0/20), which is sub-allocated into smaller CIDRs (e.g., 203.0.113.0/24). Each sub-CIDR might have its own ROUTE object, potentially announced by different ASNs (e.g., if sub-allocated to different organizations).

• Validation:

  • Network operators use ROUTE objects to validate BGP announcements.

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