Networking
IP addressing, routing, BGP, and network fundamentals.
Articles
What Is an IP Address?Learn what IP addresses are, the difference between IPv4 and IPv6, and how IP addressing works.
What Is an ASN?Understand what ASN is, how it identifies networks on the internet, and its role in BGP routing.
What Is BGP?Learn how BGP routes internet traffic between networks and why BGP security matters.
What Is Reverse DNS?Understand reverse DNS, how PTR records map IP addresses to hostnames, and why it matters for email.
BGP Routing ExplainedDeep dive into BGP routing: how autonomous systems exchange routes, BGP path selection, route propagation, and common BGP routing issues.
iBGP vs eBGP: What is the Difference?Understand the difference between iBGP (internal BGP) and eBGP (external BGP), including how they handle route propagation and when to use each.
What Is RPKI? BGP Route Origin ValidationLearn how RPKI (Resource Public Key Infrastructure) secures BGP routing by validating route origin authorizations and preventing BGP hijacks.
What Is a BGP Prefix?Understand BGP prefixes: what they are, how ASNs announce IP address blocks via BGP, and the role of CIDR notation in internet routing.
How to Find the ASN for Any IP AddressLearn how to find the Autonomous System Number (ASN) for any IP address and identify the network operator, ISP, or cloud provider that owns it.
ASN Lookup by Domain NameFind the ASN and network operator for any domain name by resolving the domain to its IP address and performing an ASN lookup.
Private ASN Ranges: 64512–65534 and 4200000000+Learn about private ASN ranges (64512-65534 for 16-bit, 4200000000-4294967294 for 32-bit), when to use them, and how they differ from public ASNs.
How to Get Your Own ASNStep-by-step guide to applying for your own ASN through ARIN, RIPE, APNIC, LACNIC, or AFRINIC. Requirements, costs, and the application process explained.
What Is IP Geolocation?Learn how IP geolocation determines the physical location of an IP address and its applications.