> ## 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.
# Configure Your Router for DIA BGP
Because router configuration commands vary by vendor and platform (Cisco, Juniper, Nokia, Palo Alto, and others), the requirements on this page are vendor-neutral. Refer to your router's documentation for the exact command syntax.
## Information Zayo provides
Zayo provides the following information for each DIA BGP connection. You'll need it to complete your router configuration:
| Value | Description |
| ------------------------------- | ----------------------------------------------------------------------------------------------------------------------- |
| **Zayo BGP peer address** | The IPv4 and/or IPv6 address your router will peer with. |
| **Zayo remote ASN** | `6461`. |
| **Customer-side IP** | The IPv4 and/or IPv6 address assigned to the customer side of the connection. |
| **BGP authentication password** | This is required, and is automatically generated. The session will not establish if this does not match on your router. |
| **Maximum prefix limit** | The maximum number of prefixes you are permitted to advertise on this session. |
## Router configuration requirements
Your router must be configured with:
| Requirement | Description |
| ----------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| **Interface and VLAN** | The customer-facing interface or subinterface must be enabled and operational, with the same VLAN ID selected in the portal (if tagged). |
| **IP addressing** | The IPv4 and/or IPv6 customer-side address assigned by Zayo for this connection. |
| **Local ASN** | Your approved customer ASN. |
| **BGP neighbor** | The Zayo BGP peer IP address, with remote ASN set to `6461`. |
| **Authentication password** | The BGP authentication password provided by Zayo. You can find this by clicking the information icon next to the DIA BGP connection under **Build Your Network > Public IPs**. |
| **Address family activation** | IPv4 unicast if IPv4 is used, IPv6 unicast if IPv6 is used. For dual-stack service, configure and validate IPv4 and IPv6 separately. |
| **Outbound route filter** | A filter that allows only the approved customer prefixes to be advertised. |
Your router must be able to reach the Zayo BGP peer IP address over the service interface, and TCP port `179` must be allowed through any firewall or ACL in the path.
## Prefix advertisement
Advertise only the public prefixes approved for your DIA BGP service. The advertised prefixes must match the approved service record. Apply outbound route filtering on your router to prevent accidental route leaks.
Do not advertise:
* Private IPv4 address space
* Link-local prefixes
* Documentation prefixes
* Internal infrastructure routes
* A default route toward DynamicLink, unless explicitly approved
* The full internet routing table
* Third-party routes not authorized for this service
* Any prefix not assigned or approved for your organization
### Prefix length
For IPv4, advertise prefixes no longer than `/24` unless explicitly approved. For IPv6, advertise prefixes no longer than `/64` unless explicitly approved. Longer prefixes may receive special routing policy handling.
### Maximum prefix limit
The number of prefixes you advertise must not exceed the maximum prefix limit for your service. If you exceed the limit, the BGP session may be protected by platform policy.
## Supported BGP communities
DIA BGP supports the following BGP communities for routing policy control. You can attach these communities to prefixes you advertise to influence how Zayo handles them.
| Community | Name | Description |
| ----------- | ------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------- |
| `6461:5990` | Blackhole | Discards traffic destined to the tagged prefix at Zayo's edge. Use for DDoS mitigation or to drop traffic to a specific destination upstream. |
| `6461:5060` | Lower preference / backup | Marks the route as a backup path. Zayo will prefer other paths to the prefix when available. |
| `6461:5100` | Peer match | Applies peer-match routing policy to the tagged prefix. |
| `6461:5180` | De-preference | Reduces the preference of the route within Zayo's network. |
| `6461:5220` | Preferred | Increases the preference of the route within Zayo's network. |
Only the communities listed above are supported for DIA BGP. Unsupported or undocumented communities may be ignored, removed, or handled differently by routing policy.
### Blackhole routing
If blackhole routing is enabled for your service, you can advertise an approved prefix with the `6461:5990` community to have traffic to that prefix discarded upstream at Zayo's edge.
Blackhole routes must be within your authorized prefix range. Use blackhole routing only when you intentionally want traffic to the advertised prefix dropped.