From a88bf464b21665ae8df6f6261f598635913ff901 Mon Sep 17 00:00:00 2001 From: "Tristan B. Velloza Kildaire" Date: Mon, 5 Dec 2022 15:56:00 +0200 Subject: [PATCH] Added back instructions from old instructions (just for now) --- docs/routing/bird/bird.md | 137 +++++++++++++++++++++++++++++++++++++- 1 file changed, 136 insertions(+), 1 deletion(-) diff --git a/docs/routing/bird/bird.md b/docs/routing/bird/bird.md index 4c6b201..5c75815 100644 --- a/docs/routing/bird/bird.md +++ b/docs/routing/bird/bird.md @@ -32,4 +32,139 @@ You can confirm that the version of BIRD you installed is version 2 with the com sudo systemctl enable --now bird ``` -This will ensure that the routing daemon starts on boot. \ No newline at end of file +This will ensure that the routing daemon starts on boot. + +## Configuration + +TODO: Re-do this sections + +The configuration template is constructed out of the following files: + +1. `filters.conf` + * Filter functions and the filter itself +2. `networks.conf` + * Advertisement of ULA +3. `tables.conf` + * The table definitions +4. `router.conf` + * This contains the needed protocol definition for discovering + your interface's prefixes and generating routes form them + * It also contains the needed protocol definitions to sync bird + routes into the Linux kernel's routing table (so you cna forward + packets based on the routes from Bird) +5. `protocols.conf` + * Depending on what protocol you want to use this will contains + configurations for each + +All of these will be included in a file saved at `/etc/bird/bird.conf` like so: + +``` +router id ; + +include "/etc/bird/crxn/tables.conf"; +include "/etc/bird/crxn/filters.conf"; +include "/etc/bird/crxn/router.conf"; +include "/etc/bird/crxn/networks.conf"; +``` + +Additionally, add the files for the route distribution protocol which we configure in the next steps. +``` +include "/etc/bird/crxn/babel.conf"; # For babel routing +include "/etc/bird/crxn/ospfv3.conf"; # For OSPFv3 routing +``` + +Remember to set a unique router ID in ``, make it anything - it doesn't have to even be an address you own. + +#### `filters.conf` + +This file holds all the required functions for subnet matching and also +filters that match to the specific prefix aggregates (regional subnets) +that CRXN uses. + +``` +filter crxnFilter +{ + if (net ~ fd00::/8) then accept; + reject; +} +``` + +#### `tables.conf` + +This file holds all table definitions. There are only two actually. +The table `crxn` is the one we actually use, `master` is optional +and is only present because if one uses `bird-lg-go` (the looking glass +we use) then it, by default, only shows routes in the `master` table. +It is meant to have the same routes as the `crxn` table. + +``` +# CRXN table +ipv6 table crxn; +``` + +#### `router.conf` + +This contains an instance of the `direct` protocol which reads the address +and prefix assigned to your AF_INET6 interfaces and generates routes from +those that represent routes to directly atrtached networks those interfaces +are on. The reason for this is that the `kernel` protocol never learns routes +in the Linux kernel's routing table that have the `kernel` protocol which +is what you get when you assign interfaces addresses and prefixes. This +doesn't even need those, it gets them from the interface. + +``` +# The kernel protocol doesn't grab kernel routes that are added by you when you assign an +# address and prefix. So instead of reading this from all routes with `proto kernel` this just +# yeets the routes off of the interface structure itself (even if you didn't have a route for your +# directly attached networks - i.e. nexthop = 0.0.0.0) +protocol direct crxnDirect +{ + ipv6 + { + table crxn; + import filter crxnFilter; + }; + # Interfaces to find neighbours on + interface "eth*"; +} + +protocol device { +} +``` + +The second part is for syncing routes from Bird to the Linux kernel's routing +table such that you can forward traffic based on the routes in Bird. + +TODO: Check, defualt `learn` should learn non `kernel` and non-`bird` routes + +``` +# CRXN Kernel protocol +# We import any routes from the kernel table other than `proto bird` and `proto kernel`, +# could be `proto static` for example. By default it will learn these. +# Of course we also then export all routes from our Bird tables into the kernel so you can actually forward packets +protocol kernel crxnKernel +{ + ipv6 { + # bird's crxn table -> kernel + table crxn; + export filter crxnFilter; + }; +} +``` + +#### `networks.conf` + +This is just something we normally add. Usually you would assign a `/64` within your ULA `/48` but you also want to claim the whole `/48` by advertising a blackhole for it. Here our `/48`/ULA is `fd40:ec65:5b4c::/48`. + +``` +protocol static crxnStatic +{ + # Advertise your /48 with a blackhole + route fd40:ec65:5b4c::/48 blackhole; + + ipv6 { + import filter crxn6; + table crxn; + } +} +```