Route filters, IRRs, and route objects

Mailman List Mirror (Read Only)
1

Hello,

I would like to ask you for an advice in regards to
"proxy registering" of customer route objects in IRR.

What is the best current practice in a situation,
when your customers want to advertise to you several
/18 or /19 but they also have a requirement to be able
to advertise some deaggregated routes on top of aggregates.

It is very common that they are unable to predict exactly
which deaggregated routes they will need to advertise,
as they use those to achieve some traffic engineering
objectives which change over time. And "over time" does
NOT occur once per 30 minutes or so, so they DON'T
generate any major BGP fluctuations.

Forgive my ignorance, but is my understanding of RPSL
correct, that it should be possible to specify routes
in a way which will allow cover aggregate plus whole
set of possible more specific routes upto certain netmask
length. Something like: 10.0.0.0/18^18-24

So why this is uncommon to use such notation to describe
routing policy, and use it to generate filters?

Why it is required by some providers to generate explicit,
exact route objects, in order to allow routes through
their filters?

Is it really necessary to "explode" route-sets like
those 10.0.0.0/m^m-n into 2^(n-m+1) separate route objects
to meet requirements of some providers?

I believe that this is very common problem, so if there
are any places on the web with some "best practice"
documents, please point me to them.

Thank you,

Przemek

2

Yes,

This is true, and I am using cisco prefix list already,
and "upto" notation on juniper boxes.

The problem is that some providers (like LEVEL3)
requires that all routes are registered in some IRR
before they will consider them valid/legitimate....

So I have filters accepting from my customers whatever le 24,
but once those routes are propagated over Internet and they
reach eventually providers like Level3, they have their filters
accepting only those routes, which are registered on some IRR
in exact way....

Przemek

3

So I have filters accepting from my customers whatever le 24,
but once those routes are propagated over Internet and they
reach eventually providers like Level3, they have their filters
accepting only those routes, which are registered on some IRR
in exact way....

Are you sure that level3 filters external routes against all IRR, or
(likely) is it just routes they are willing to hear their own from
customers?

If they filter global routes in the way you describe then I believe
their customer base will be disappointed once the radb purges unpaid
objects on April 2 (http://www.radb.net/)

-mark

4

I worked on the assumption that the customer would think about what they were doing if they had to register them all. It didn't stop people doing it but I think it generated more discussion on what they really wanted to achieve than if we just allowed it automagically.

Mark.