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IRRDB Prefixes and ASN Filtering

Prerequisite Reading: Ensure you first familiarize yourself with the generic documentation on managing and generating router configurations here.

IXP Manager can maintain a list of member route:/route6: prefixes and origin ASNs as registered in IRRDBs in its database and then use these to, for example, generate strict inbound filters on route servers.

Setup

You need to have set up some IRRDB sources (e.g. RIPE's whois service) under the IXP Admin Actions / IRRDB Configuration on the left hand side menu. If you do not have any entries here, there is a database seeder you can use to install some to start you off:

cd $IXPROOT
./artisan db:seed --class=IRRDBs

BGPQ3 is a very easy and fast way of querying IRRDBs. You first need to install this on your system. On a modern Ubuntu system this is as easy as:

apt install bgpq3

Then configure the path to it in your .env file.

# Absolute path to run the bgpq3 utility
# e.g. IXP_IRRDB_BGPQ3_PATH=/usr/local/bin/bgpq3
IXP_IRRDB_BGPQ3_PATH=/usr/bin/bgpq3

Usage

To populate (and update) your local IRRDB, run the following commands:

cd $IXPROOT
php artisan irrdb:update-prefix-db
php artisan irrdb:update-asn-db

From IXP Manager v5 onwards, and so long as your bgpq3 path is set as above and is executable, the task scheduler will take care of updating your local IRRDB a number of times a day. If you are using a version of IXP Manager before v5, then the above commands should be added to cron to run ~once per day (using the --quiet flag).

There are four levels of verbosity:

  1. --quiet: no output unless there's an error / issue.
  2. no option: simple stats on each customer's update results.
  3. -vv: include per customer and overall timings (database, processing and network).
  4. -vvv (debug): show prefixes/ASNs added remove also.

You can also specify a specific customer to update (rather than all) with an additional free form parameter. The database is searched for a matching customer in the order: customer ASN; customer ID (database primary key); and customer shortname. E.g.:

php artisan irrdb:update-prefix-db 64511

Internal Workings

Essentially, based on a customers AS number / IPv4/6 Peering Macro, IXP Manager uses bgpq3 to query IRRDBs as follows:

bgpq3 -S $sources -l pl -j [-6] $asn/macro

where $sources come from the IRRDB sources entries.

Or, a real example:

bgpq3 -S RIPE -l pl -j AS-BTIRE
bgpq3 -S RIPE -l pl -j -6 AS-BTIRE

Details

The IRRDB update commands will:

  • iterate over all route server client customers for IPv4 and IPv6 (unless a specific customer is specified);
  • use the appropriate AS macro or ASN;
  • query the RADB against the appropriate source set for that customer;
  • compare prefixes(/ASNs) in the database already (if any) against RADB and insert / delete as appropriate;
  • validate the prefix for proper CIDR notation before database inserts;
  • update the last_seen time for all prefixes(/ASNs) for that customer;
  • create a local file-based cache of that customer's prefixes / asns to speed up router configuration generation (you don't need to worry about the staleness of this cache as it's cached everytime the IRRDB commands above are run for each customer).

We use transactions to update the database so, even in the middle of a refresh, a full set of prefixes for all customers will still be available. It also means the update process can be safely interrupted.

Note that our current implementation only queries RADB as BGPQ3 does not support the RIPE whois protocol. Our version will however set the RADB source database according to the member's stated IRRDB database as set on the customer add / edit page - so, for customer's registered with the RIPE IRRDB, the RIPE database of RADB is queried.