William some recommended practises, although you can point out your specific constraints in adopting any.
- Define the Internet as a VRF?
(Yes Logical speperation is the way to go.)
- Use private ASNs?
(No, use a Public AS, you may have to peer outside your AS in a VRF with other AS's)
- Define a VRF per special service?
(This is Perfect , Logical Seperation)
- Use at least two route reflectors?
(Right, atleast 2 and above that depends on the size of your network)
- Use OSPF as IGP?
(I dont see any problems with OSPF in scaling for big networks)
- Limit the CE-PE routing support to OSPF and BGP?
(This aspect shouldnt impact much really, you can very well support all the protocols, as its more of serving your customers, rather than dictating the conditions.
Yes have a seperate VRF for Device Managements (also give a thought for a management subnet, which would be unique across your network)
You should generally start with a overview topology, introdcution of the objectives. And then go ahead with the suggested phy topo,
And then move on to the logical services, beggining from Core IGP, then core BGP, and then all the add on protocols, multicast , MPLS TE etc/. Then you can cover specilized service and their logic and description in the end.
Pretty much, just simply think of building out right from scratch that is Physical Layer and Move to Layer 2 and then Layer 3 Layer 4 .
So basically you doc should be index in a manner following the sequence of the OSI layers, this gives a good flow to the doc. And rest remains is the description of the logic used in each service or deployment method, that would be your skill.
HTH-Cheers,
Swaroop
