Core routers shouldn't need to originate prefixes

[bswinnerton]

Ideally we'd be able to leave out the originations key in the configurations of Core routers:

peering/config/router.fqdn.example.yml

Lines 67 to 72 in 0befb58

	# The prefixes being originated by this router
	originations:
	v4:
	- '198.51.100.0/24'
	v6:
	- '2001:db8::/32'

But they are currently powering things like:

peering/templates/bird.conf.erb

Lines 7 to 21 in 0befb58

	define ORIGINATED_PREFIXES_4 = [
	<%= config.originations.v4.join(",\n ") %>
	];
	define ORIGINATED_PREFIXES_6 = [
	<%= config.originations.v6.join(",\n ") %>
	];
	define OUR_INTERNAL_PREFIXES_4 = [
	<%= config.originations.v4.map { |p| "#{p}+" }.join(",\n ") %>
	];
	define OUR_INTERNAL_PREFIXES_6 = [
	<%= config.originations.v6.map { |p| "#{p}+" }.join(",\n ") %>
	];

Which are later used in:

peering/templates/bird.conf.erb

Lines 194 to 210 in 0befb58

	function is_own_prefix() {
	if net.type = NET_IP4 then {
	if net ~ ORIGINATED_PREFIXES_4 then {
	bgp_large_community.add((OUR_AS, 101, 1));
	return true;
	}
	}
	if net.type = NET_IP6 then {
	if net ~ ORIGINATED_PREFIXES_6 then {
	bgp_large_community.add((OUR_AS, 101, 1));
	return true;
	}
	}
	return false;
	}

And:

peering/templates/bird.conf.erb

Lines 212 to 218 in 0befb58

	function is_own_internal_prefix() {
	if net.type = NET_IP4 then
	if net ~ OUR_INTERNAL_PREFIXES_4 then return true;
	if net.type = NET_IP6 then
	if net ~ OUR_INTERNAL_PREFIXES_6 then return true;
	return false;
	}

Perhaps we can separate the idea of "originations" from "IPs that are ours". The main goal here being that we are able to filter out any prefixes by customers who peer with core routers that may accidentally announce our own prefixes.