[j-nsp] Policy based routing with redundancy

[Nicolaj Kamensek]

Hi list,

I could need a little help with the following setup since my Juniper 
experience is rather limited yet because we are going to migrate our 
network to juniper within the next months.

Here is what I want to setup:

* There is 3 full-feeds: A, B and C
* Another upstream D with just DeCIX prefixes(german exchange point)
* 2 different routing-options depending on the customer's needs

Routing 1:

* local-pref 300 on upstream D to prefer the exchange prefixes
* local-pref 200 on upstream A
* local-pref 100 on upstream B which is only used for backup purposes


Routing 2:

* local-pref 300 on upstream D to prefer the exchange prefixes
* local-pref 200 on upstream C which is the main transit for this 
routing table
* local-pref 100 on upstream B, again only for backup


So both routing-instances shall have a backup transit if the main 
transit fails


Which routing decision is made based upon two things:

* a prefix-list consisting of some of my own prefixes OR
* a bgp community I set when I accept the prefixes of my customers(e.g. 
65000:2000 for Routing 1 and 65000:3000 for Routing 2)

Just to mention it: the hardware is a Juniper M20 with SSBv1, so there 
is "only" 8MB SDRAM for the forwarding-table and therefore the table is 
limited to about ~400k entries unless the heap is full

A, B and C send all about 200k prefixes, D consists of ~50k prefixes


Hope for some pointers to the right direction or even more :-)

Thanks in advance!

Regards,
Nicolaj Kamensek