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Autonomous System Number (AS Number) Queries

This page provides detailed information about querying Autonomous System Numbers (ASNs) using the RDAP command line client.

Basic AS Number Queries

Simple AS Number Lookup

Query information about a specific Autonomous System Number:

rdap as64496

This command will: - Automatically detect that "as64496" is an AS number - Use the RDAP bootstrap process to find the appropriate Regional Internet Registry (RIR) - Display AS information

Explicit AS Number Type Specification

You can explicitly specify the query type to avoid automatic inference:

rdap -t autnum as64496

AS Number Formats

Standard AS Number Format

The most common format uses the "as" prefix followed by the number:

rdap as64496

Numeric-Only Format

You can also query using just the numeric portion:

rdap 64496

Server Targeting Options

Bootstrap Registry Selection

Direct queries to a specific RIR using its bootstrap identifier:

# Query ARIN specifically
rdap -b arin as64496

# Query RIPE NCC
rdap -b ripe as65536

# Query APNIC
rdap -b apnic as13335

Common RIR identifiers for AS numbers: - arin - American Registry for Internet Numbers - ripe - RIPE Network Coordination Centre
- apnic - Asia-Pacific Network Information Centre - lacnic - Latin America and Caribbean Network Information Centre - afrinic - African Network Information Centre

Explicit Server URL

Direct queries to a specific RDAP server:

rdap -B https://rdap.arin.net/registry/autnum/64496

This bypasses the bootstrap process and sends the query directly to the specified server.

INR Backup Bootstrap

When normal bootstrapping fails for AS numbers, you can specify a backup:

# Use ARIN as backup (default)
rdap --inr-backup-bootstrap arin as64496