How does it work?

There are two route servers which hold details of the routes exchanged at the 3CIX. These servers filter routes in two ways:

1. Incoming announcements are checked against individual filter lists for each peer.
   
2. Outgoing announcements are filtered to make sure that routes are not announced for RFC1918 addresses and other bogon or martian addresses.

The filter lists and other details of the route server configuration are built automatically from an RPSL database using the RtConfig tool from the IRRToolset. If you need to change the prefixes you want to announce you can use the Change 3CIX Route filters tool.

More information on using RPSL is available from the APNIC page About the APNIC Routing Registry. For a number of reasons we run our own Routing Registry Database at present. The 3CIX Routing Registry data is available either by using a standard whois client connected to:

• whois.nzix.net:43

or using a web based interface:

• NZRR Routing Registry Database

You can examine the 3CIX routing policy by looking up the details for AS24385

A list of the Autonomous Systems connected to the route servers are given in the RPSL as-set object AS24385:AS-PUBLIC. The AS numbers in this list have been assigned by one of the Regional Internet Registries such as APNIC.

Each AS has a list of networks they announce to the route servers given in an RPSL route-set object. For example, the numbers that CityLink announce to the 3CIX are given by AS24385:RS-ROUTES:AS23754 and incoming announcements are checked against filters constructed from these lists. If you are a 3CIX peer, you can check the list of networks that you are allowed to announce to the 3CIX by looking up the relevant route-set AS24385:RS-ROUTES:AS<YOUR_AS>. Please get in touch with us with any corrections.

The list of exported routes is checked against an RPSL filter-set called fltr-bogons which is constructed from two other filter-sets fltr-martian and fltr-unallocated Thanks to Rob Thomas at Team Cymru for these filters.