fix(interlink): add tags

Author: RoRoJ

pages/interlink/reference-content/bgp-communities.mdx

@@ -0,0 +1,31 @@
+---
+meta:
+  title: Using BGP community tags with InterLink
+  description: Learn how to use BGP community tags to set local preference for incoming traffic via Scaleway InterLink.
+content:
+  h1: Using BGP community tags with InterLink
+  paragraph: Learn how to use BGP community tags to set local preference for incoming traffic via Scaleway InterLink.
+tags: interlink configuration border-gateway-protocol bgp-tags local-preference local-pref
+categories: 
+  - interlink
+  - network
+dates:
+  validation: 2025-03-26
+  posted: 2025-03-26
+---
+
+You can use **B**order **G**ateway **P**rotocol (BGP) communities on outgoing routes (advertized by Scaleway VPC) and incoming routes (advertized by your external router). TODO CHECK? 
+
+A BGP community is a group of IP prefixes that share a common attribute.
+
+Scaleway makes available three tags for the **Local Preference** attribute. This attribute lets you influence load balancing and route preference for traffic. For each prefix that you advertize over a BGP session, you can apply one of the following local preference community tags to indicate the priority of the associated path for returning traffic:
+
+- `12876:42050` — Low preference
+- `12876:42100` — Medium preference
+- `12876:42200` — High preference
+
+Local preference BGP community tags are evaluated in order from lowest to highest preference, where the highest preference is preferred.
+
+These tags are mutually exclusive, meaning you can only apply one of them per prefix.
+
+To apply these community tags, you must configure your BGP router or software to add the appropriate community to the routes you advertise.