IXP

Also known as: Internet Exchange Point, Internet Exchange

Internet Exchange Point — a shared Layer 2 fabric where many networks meet to exchange traffic via public peering, usually through a route server and BGP sessions.

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What is an IXP?

An IXP (Internet Exchange Point) is a physical location — usually a carrier-neutral data center or a set of facilities in a metro area — hosting a shared Ethernet fabric that many networks plug into. Each participant can set up peering sessions with any other participant across the fabric. Major IXPs include DE-CIX in Frankfurt, AMS-IX in Amsterdam, LINX in London, MSK-IX in Moscow, and Equinix's worldwide IX footprint.

Why IXPs exist

IXPs solve a scaling problem. A network that wanted to peer bilaterally with 500 other networks would need 500 cross-connects, 500 BGP sessions, and 500 peering agreements. At an IXP it needs one port, one cross-connect to the fabric, and — through a route server — a single BGP session that effectively peers it with every other route-server participant at once. Costs collapse, latency drops (traffic stays local instead of transiting a distant upstream), and resilience improves.

IXPs in IP investigations

Looking up the ASN of an IP and listing which IXPs it is present at (via PeeringDB and similar public databases) tells you the shape of a network: which metros it operates in, how well-connected it is, and who its likely peers are. A residential ISP with presence at three major IXPs looks very different from a suspicious /24 announced by an AS with no IX presence at all.

See the AS, upstream transit, and network context for any IP in our WHOIS lookup tool.

Frequently Asked Questions

A data center is a building full of servers and network gear. An IXP is a shared Layer-2 fabric — typically inside one or more carrier-neutral data centers — where many networks plug in to exchange traffic with each other. You can colocate a server in a data center without joining the IXP; you can join the IXP without owning any servers there. Most large IXPs (DE-CIX, AMS-IX, LINX, Equinix Internet Exchange) span multiple data centers in a metro area connected by dark fiber.
Variable but usually moderate. Membership fees range from free (for some smaller community IXPs) to a few thousand dollars per year. Port costs are typically $300-$2,000 per Gbps per month at major IXPs, with bigger 100 Gbps and 400 Gbps ports costing more in absolute terms but less per Gbps. You also need a local cross-connect from your equipment to the IXP fabric, which is a one-time install fee plus monthly port fee at the data center.
A route server is a single BGP speaker on the IXP fabric that participants peer with once and effectively reach every other route-server participant. Without it, peering with 500 networks at the IXP would require 500 individual BGP sessions; with the route server, you peer once and get multilateral exchange. Route servers also implement the IXP's filtering policy (drop bogons, validate RPKI, limit max prefixes) so each participant doesn't have to.
The biggest by traffic and member count are concentrated in Europe and Asia: DE-CIX Frankfurt (peak ~17 Tbps, 1,100+ members), AMS-IX Amsterdam, MSK-IX Moscow, LINX London, JPNAP Tokyo, HKIX Hong Kong, and SIX Seattle in the US. Equinix operates the world's largest IXP footprint by city count, with exchanges in 40+ metros. Smaller regional and national IXPs are critical local infrastructure even if they don't make the global top-20.
Lower latency to the destinations they use most. When the user's ISP and a content provider both peer at a local IXP, packets stay in the metro area instead of looping through a distant transit hub — saving 20-100 ms each direction. Latency-sensitive applications (gaming, voice, video calls) benefit most. Areas without nearby IXPs (much of sub-Saharan Africa, parts of South America, rural regions worldwide) have noticeably worse internet performance even on otherwise modern connections.