---
name: direct-link-layer-2-layer-3
title: Comparing Layer-2 and Layer-3 connections for Direct Link
description: IBM Cloud® Direct Link accepts OSI Layer-2 and Layer-3 partner interconnections from network service providers (NSPs). Some network service providers offer services for both of these layers on different networks, however, some providers might choose **not** to interconnect all of their networks into IBM Cloud.
last-updated: 2024-10-09
---

> ## Documentation Index
> The table of contents for this documentation set is at https://cloud.ibm.com/docs/direct-link?format=markdown
> The index for all IBM Cloud docs is at: https://cloud.ibm.com/docs/llms.txt
> Use these files to discover more information as needed.

# Comparing Layer-2 and Layer-3 connections for Direct Link
{: #comparing-layer-2-layer-3}

IBM Cloud® Direct Link accepts OSI Layer-2 and Layer-3 partner interconnections from network service providers (NSPs). Some network service providers offer services for both of these layers on different networks, however, some providers might choose **not** to interconnect all of their networks into IBM Cloud.
{: shortdesc}

When planning your IBM Cloud Direct Link deployment, consider the characteristics that are associated with Layer-2 and Layer-3 connections, so you can create a deployment that best suits your needs.

## Considerations for Layer-2 connections
{: #layer-2-networks}

For each VLAN-based virtual circuit, which you create with a Layer-2 partner interconnection, you must configure and establish a BGP session between your on-premises routers and the IBM Cloud XCR. IBM Cloud provides you with a `/31` IPv4 assignment to establish a BGP session with your router.

* Layer-2 networks offer options for simple one-to-one connections between enterprises and IBM Cloud.
* Layer-2 services rely on VLANs instead of IP addresses.
* Layer-2 services might be lower cost and lower latency, and they might consume less overhead than Layer-3 services.
* Layer-2 networks do not impose restrictions on the Layer-3 features that an enterprise can enable.

## Considerations for Layer-3 connections
{: #layer-3-networks}

For Layer-3 connections, for each virtual circuit, your service provider establishes a BGP session between IBM Cloud XCRs and the provider's edge routers. You do not need to configure BGP with IBM Cloud for your on-premises router because your service provider manages the BGP configuration to IBM Cloud. **This means when you order Direct Link Connect via the IBM Portal, you need to populate the Layer 3 providers ASN for the BGP session, not your customer ASN**

* Layer-3 IP VPN or AVPN networks enable "any-to-any" connectivity.
* Layer-3 networks require the network service provider to maintain a BGP session between the enterprise and IBM Cloud.
* Certain network service providers might restrict certain functionalities across their network when using Layer-3 connections, such as ASN prepend, GRE tunneling, and so forth. Be sure to check with your provider about possible restrictions.

## Partner interconnection table
{: #partner-interconnection-table}

The following table summarizes the type of connections that each IBM Cloud partner provides.

| Partners | Interconnection type |
|-------|-------|
| Bell Canada | **Layer 3** |
| British Telecom | **Layer 3**  |
| CenturyLink IP VPN | **Layer 3** |
| CenturyLink Dynamic Connections | Layer 2 |
| Chief Telecomm | Layer 2 |
| China Unicom | **Layer 3** |
| Colt | Layer 2  |
| Console Connect | Layer 2 |
| Epsilon | Layer 2 |
| EU Networks | Layer 2 |
| IBM BlueFringe | **Layer 3** |
| Intercloud | **Layer 3** |
| IXReach | Layer 2 |
| Neutrona | Layer 2 |
| nextGen GNPP | **Layer 3** |
| NTT | **Layer 3** |
| Orange Business Services | **Layer 3** |
| PacketFabric | Layer 2  |
| Softbank | **Layer 3** |
| SES Networks | Layer 2  |
| Tata IZO™ Private Connect  | **Layer 3** |
| Arelion | **Layer 3** |
| Tokai | Layer 2 |
| Vodafone| **Layer 3** |
| Zayo Cloud Link | Layer 2 |
{: caption="Partner interconnection table" caption-side="bottom"}