add networking

docs/src/networking.md

@@ -1,18 +1,53 @@
-# Networking
+# Network Configuration Documentation
+
+## Overview
+
+This document outlines the BGP routing configuration for our multi-homed network
+with connections to various internet exchanges and transit providers in Bangkok,
+Hong Kong, Singapore, and Europe. Currently 3x 10G fibers are used for uplinks.
 
 ## Bandwidth
 <img src="images/networking/bandwidth.webp" alt="Scaling bandwidth" style="width: 100%; margin-top: 2em; object-fit: cover;">
 
-3x 10G uplink connections are used to connect to WAN utilizing BGP routing
-protocol.
+## BGP Community Structure
+
+We use BGP communities to classify and manage routes based on their origin and characteristics. Our community format is `AABBCC`, where:
+
+- `AA`: Region/Type
+  - `10`: Local (Bangkok)
+  - `20`: Regional
+  - `30`: Remote
+- `BB`: Provider
+  - `10`: BKNIX
+  - `20`: AMS-IX
+  - `30`: IPTX
+  - `40`: Reserved for future use
+- `CC`: Connection Identifier
+  - `00`: Primary connection
+  - `01-99`: Additional connections, ordered by preference
+
+### Key Communities
+
+- 101000: BKNIX Primary (Local 10G - Bangkok)
+- 102000: AMS-IX Bangkok Primary (Local 1G - Bangkok)
+- 201000: AMS-IX Hong Kong Primary (Regional 200M - Hong Kong)
+- 203000: IPTX Singapore Primary (Regional 500M - Singapore)
+- 203001: IPTX Hong Kong Secondary (Regional 500M - Hong Kong)
+- 302000: AMS-IX Europe Primary (Remote 100M - Amsterdam)
+
+## Routing Configuration
+
+| Name              | Speed | Path Prepend | MED | Local Pref | Community    | Description        | Edge Router |
+|-------------------|-------|--------------|-----|------------|--------------|--------------------| ----------- |
+| BKNIX             | 10G   | 0            | 50  | 200        | 142108:101000| LOCAL-BKNIX-PRIMARY | BKK10       |
+| AMS-IX Bangkok    | 1G    | 0            | 100 | 190        | 142108:102000| LOCAL-AMSIX-PRIMARY | BKK20       |
+| IPTX Singapore    | 500M  | 1            | 150 | 185        | 142108:203000| REGIONAL-IPTX-SG-PRI| BKK20       |
+| IPTX Hong Kong    | 500M  | 1            | 150 | 180        | 142108:203001| REGIONAL-IPTX-HK-SEC| BKK10       |
+| AMS-IX Hong Kong  | 200M  | 2            | 200 | 170        | 142108:201000| REGIONAL-AMSIX-HK-PRI| BKK10      |
+| AMS-IX Europe     | 100M  | 3            | 300 | 160        | 142108:302000| REMOTE-AMSIX-EU-PRI | BKK20       |
 
-## Routing
+## Traffic Engineering Principles
 
-| Name              | Speed         | Path Prepend  | MED       | Description          | Edge Router | Chain Name              | Rule                                                      |
-|-------------------|---------------|---------------|-----------|----------------------|-------------|-------------------------|-----------------------------------------------------------|
-| BKNIX             | 10G           | 0             | 50        | LOCAL-BKNIX          | BKK10       | BKNIX-OUT-v4, BKNIX-OUT-v6 | `set bgp-out-med 50; accept;`                               |
-| AMS-IX Bangkok    | 1G            | 0             | 100       | LOCAL-AMSIX-BKK      | BKK20       | AMSIX-BAN-OUT-v4, AMSIX-BAN-OUT-v6 | `set bgp-out-med 100; accept;`                              |
-| IPTX Singapore    | 500M (paid)   | 1             | 150       | REGIONAL-IPTX-SG     | BKK20       | HGC-SG-OUT-v4, HGC-SG-OUT-v6 | `set bgp-path-prepend 1; set bgp-out-med 150; accept;`      |
-| IPTX Hong Kong    | 500M (paid)   | 1             | 150       | REGIONAL-IPTX-HK     | BKK10       | HGC-HK-OUT-v4, HGC-HK-OUT-v6 | `set bgp-path-prepend 1; set bgp-out-med 150; accept;`      |
-| AMS-IX Hong Kong  | 200M          | 2             | 200       | REGIONAL-AMSIX-HK    | BKK10       | AMSIX-HK-OUT-v4, AMSIX-HK-OUT-v6 | `set bgp-path-prepend 2; set bgp-out-med 200; accept;`      |
-| AMS-IX Europe     | 100M          | 3             | 300       | REMOTE-AMSIX-EU      | BKK20       | AMSIX-EU-OUT-v4, AMSIX-EU-OUT-v6 | `set bgp-path-prepend 3; set bgp-out-med 300; accept;`      |
+1. Local Preference: Higher values indicate more preferred routes. Local routes are preferred over regional, which are preferred over remote routes.
+2. MED (Multi-Exit Discriminator): Lower values are preferred. Used to influence inbound traffic when other attributes are equal.
+3. AS Path Prepending: Increases AS path length to make a route less preferred. Used for coarse control of inbound traffic.