What Is an ISP and ASN Lookup?

An IP address can tell you more than the number.

With the right lookup, you can often see the internet service provider, organization, usage type, and ASN behind the connection.

The T.LY What Is My IP Address tool shows ISP and ASN details for your current public IP. If you want to inspect a different address, use the IP Address Lookup tool.

What is an ISP lookup?

An ISP lookup identifies the internet service provider or network associated with an IP address.

ISP stands for Internet Service Provider.

For a home user, that may be a cable, fiber, or mobile internet company. For a server, it may be a cloud provider, data center, hosting company, or company network.

ISP data can help answer:

• Who provides this connection?
• Is this traffic coming from a residential ISP?
• Is this traffic coming from a data center?
• Is this connection using a VPN or hosting network?
• Which provider should be contacted for abuse or network issues?

What is an ASN?

ASN stands for Autonomous System Number.

An autonomous system is a network or group of networks managed under a common routing policy. Large ISPs, cloud providers, universities, data centers, and companies can operate autonomous systems.

The ASN helps identify the routed network that announces an IP address on the internet.

For example, an IP address might belong to:

• a residential ISP network
• a mobile carrier
• a cloud hosting provider
• a VPN provider
• a company network
• a university network

The ASN is useful because it gives you a network-level view, not just a single IP address.

ISP vs ASN

ISP and ASN are related, but they are not exactly the same.

Field What it tells you ISP Provider or service associated with the IP Organization Company or entity tied to the network record ASN Routed network announcing the IP address Usage type Whether the IP appears residential, business, hosting, mobile, or similar Sometimes the ISP and organization are the same. Sometimes they differ because of resellers, hosting arrangements, VPN providers, or data center networks.

Why ISP and ASN lookups are useful

ISP and ASN lookups are helpful when you need more context around traffic.

Common uses include:

• diagnosing network problems
• checking whether a VPN or proxy is active
• reviewing suspicious login attempts
• understanding server or API traffic
• setting firewall allowlists
• investigating abuse reports
• validating analytics patterns
• routing support tickets to the right provider

For example, if a user says they are connecting from a home network but the ASN belongs to a data center, that may explain why a security system treats the request differently.

How to find your ISP and ASN

Open What Is My IP Address.

The tool checks your current public IP address and shows network details such as:

• ISP
• organization
• ASN
• usage type
• country, region, and city
• VPN or proxy signal

If you need to check a different IP address, use IP Address Lookup and paste the address you want to inspect.

Why ISP or ASN data may be missing

Not every lookup returns every field.

ISP or ASN data may be missing, stale, or slightly different between providers because:

• IP ranges move between networks
• providers update records at different speeds
• private or internal addresses are not public internet addresses
• some databases classify networks differently
• VPNs and proxies can obscure the expected provider

If the data looks wrong, compare multiple fields instead of relying on one label. The IP address, organization, ASN, usage type, and location together usually tell a better story.

ISP and ASN in link analytics

For link management, ISP and ASN context can be useful when reviewing traffic quality.

A normal campaign may get traffic from residential ISPs, mobile carriers, work networks, and public Wi-Fi. A suspicious pattern may involve unusual hosting providers, repeated data center traffic, or VPN-heavy activity.

You do not need to overreact to one network label. But the context helps when you are troubleshooting, reviewing fraud signals, or trying to understand where clicks are coming from.

ISP and ASN lookup summary

An ISP lookup tells you the provider behind an IP address.

An ASN lookup tells you the routed network announcing that IP address.

Together, they help explain what kind of network a request came from and whether it looks like a home ISP, mobile network, business connection, data center, VPN, or proxy.

Start with What Is My IP Address for your current connection, or use IP Address Lookup to inspect any public IP address.