OSPF design

RouterOS Forwarding Protocols
1

HI!!

What would be the best approach?

CONSIDER A MUCH LARGER NETWORK, THIS IS JUST AN EXAMPLE

OPTION A: a larger AREA0 with many small stub areas.

  • Advantage: I can summarize the PPPoE clients
  • Disadvantages: larger AREA0

OPTION B: smaller AREA0 with larger AREA1

  • Advantage: smaller AREA0
  • Disadvantages:
  • I can summarize the PPPoE clients but only in R2
  • larger AREAX… maybe?

OPTION C: mix between A and B… or something like that… (less likely, but I still put it)

On the PPPoE servers there are hundreds of clients, so I need to summarize.

Thanks!

2

If you’re going to redesign, it’s better to use OSPF, MPLS and BGP together in a design like this:

  • Much better scale
  • Summarization without area constraints
  • Putting only ptp and loopbacks into OSPF improves convergence time sigificantly
  • MPLS can be used to aggregate PPPoE sessions to fewer locations

For more general information about iBGP/OSPF/MPLS (not {PPPoE specific) read this article:

https://stubarea51.net/2020/03/03/starting-a-wisp-guide-to-selecting-a-routing-architecture/

To use redundant BRAS for scale - read this article

https://stubarea51.net/2018/04/23/pppoe-high-availability-design-incorporating-multiple-access-concentratorsbras/

3

Excellent information, i’ll read it. Thank you!!