I have been using router os for bgp for a few years now, we have 3 upstream providers peered at the moment (3 full views), we have our own AS and several IP blocks from RIR. One of our customers has ASN and their own IP block and would like to peer with us (full view). How would I go about setting up the downstream peer and my current peers so that the customers ip block is advertised upstream?

I have already sent LOA to upstreams and they have adjusted their filters for the my customers block.

I have setup my out-filter on my upstream peers to accept my blocks and my customers block and to discard the rest.

I have setup my in-filter on the downstream customer to accept their ip block, discard the rest.

I was thinking i need to check off redistribute-other-bgp on my upstream instance and the a new downstream instance, is there anything else I need to do?

You are over thinking it....

Upstream Providers or DownStream Customers ..... the BGP is configured in pretty much the same manner, with the exception of filters... (You should be using some method of filtering the sent & received routes )

For an upstream peer, you are advertising Your IP Blocks, and expecting to receive the Full table.
For your downstream customer, you are going to be Sending them Full Route and expecting to receive from the Their IP Blocks.

To advertise your cusotmer's IP Block to your Up-Stream peer, have them open / adjust the filters (which you did),
and simply adjust your Filters (out filter) to include your DownStream Customer's IP Block.

Simple....

You can make it complex if you choose some complex filtering schemes or start adjusting other parameters... (med, local pref, communities etc).

Faisal

Awesome, thanks for your reply faisali.

So, do I need to have redistribute-other-bgp checked in the instance? Previously I had nothing checked off and was using the networks tab to advertise my blocks.

The only time you would want to use 'redistribute-other-bgp' is if you have multiple BGP instances (not peers), and wish to leak routes between the instances.

Typically, one would not use multiple BGP instances except internally, such as using separate private ASNs for L2/3VPNs and different classes of management IPs. Unless you have a very specific reason to do so, and have a very clear idea of how it works, I would avoid it.

--Eric