> ## Documentation Index
> Fetch the complete documentation index at: https://docs.zayo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Dedicated Internet Access (DIA) Overview

Dedicated Internet Access (DIA) provides a dedicated, uncontended link to the internet for critical applications that need guaranteed bandwidth and performance. Unlike shared internet connections, DIA offers exclusive access to your allocated bandwidth, ensuring consistent performance and reliability.

* **Dedicated Bandwidth**: Exclusive access to your allocated bandwidth without contention from other users
* **Symmetrical Performance**: Equal upload and download speeds for consistent bidirectional performance
* **Guaranteed Performance**: Predictable latency and throughput for mission-critical applications
* **Direct Routing**: Traffic is routed directly from your service to the internet via a dedicated circuit

## DIA vs. DIA BGP

You can create a standard DIA connection or a DIA BGP connection.

Both connection types provide the same dedicated, uncontended internet access. The difference is who supplies the IPs and how routing is established.

* A standard DIA connection uses public IP addresses assigned by Zayo, with routing handled entirely by Zayo's network. Standard DIA is simpler to provision and requires no router configuration on your side.
* A DIA BGP connection uses your own public IP addresses and ASN, advertised to Zayo's network over a BGP session between your router and ours. DIA BGP requires more setup, including ASN approval and BGP configuration on your router, but gives you control over your public IP space and how your traffic is identified on the internet.

## Key components

### Public IP addresses

Standard DIA connections require public IP addresses, which you can provision in [DynamicLink](public-ips). These are ranges of public IP addresses specifically reserved for dedicated internet access services. You can:

* Request new public IP blocks from the **Public IPs** tab
* Select existing IP blocks when creating a DIA connection
* Use IPv4 or IPv6 addresses
* Configure subnet sizes (typically `/30` for standard connections)

If you already own public IP space and want to advertise it over your DIA connection, you can use [DIA BGP](dia-bgp) instead of requesting IPs from Zayo.

### Autonomous System Number (ASN)

DIA BGP connections require an ASN.

An ASN is a unique identifier assigned to your network that allows it to participate in BGP routing on the internet.

You must [submit your ASN](asn) in DynamicLink and have it approved before you can build a connection.

### Ports

A physical port is required to establish a DIA connection. The port must be:

* Deployed in the physical location where you wish to route traffic
* Have sufficient available bandwidth for your desired connection speed
* Configured with appropriate VLAN settings

### Virtual interfaces (VLANs)

DIA connections use VLANs to segment traffic on your port. You can:

* Specify a VLAN ID for tagged traffic
* Use "Native" for untagged connections
* Configure multiple DIA connections on the same port using different VLANs

## Advanced features

### DIA firewall

The DIA Firewall protects your connection by filtering traffic. By default:

* All outgoing traffic is allowed
* All incoming traffic is blocked

You can create custom firewall rules to:

* Allow specific inbound services (e.g., SSH, web servers)
* Block unwanted outbound traffic
* Apply web filtering for granular access control

### Network Address Translation (NAT)

NAT allows devices in your private network to access the internet using your DIA connection's public IP address. You can configure:

* **Source NAT**: Translate private IPs to your DIA's public IP
* **1:1 NAT**: Map a single private IP to a single public IP
* **Port Forwarding**: Forward specific ports to internal services