Impact of PBR on SDWAN Solution

[j-tadros]

We are in the process of deploying SDWAN to our infrastructure and I heard on multiple occasions that PBR on existing infrastructure is and will impact the SDWAN integration. I'd like to understand how does PBR impact the SDWAN in general and if I have to work in phased to migrate the legacy infrastructure to the SDWAN what are the best practices steps to consider? What are other consideration from different perspectives do I need to have heads-ups on in order to complete this solution? Thank you!

[Flavio Miranda]

hi

 PBR - Policy-Based  Routing  should not impact anything. This is just a matter on how you handle you traffic. For example, if you are deploying QoS over a link, you need to classify your traffic so that you are able to apply different bandwidth depending on the traffic priority.

 About migration in phases or not depends on your environment size. If we are talking about a very large network infrastructure, of course you are going do this in phases. It´s impossible to transform a huge network from legacy to a SDWAN during one night.

 Best pract is deploy the network core (vManage, vBound, vSmarts) , consigure everyting, test everything. Then, migrate a small site or deploy one cEdge in your lab just to make sure everything is OK.

  Some consideration I advise you t is routing table size, ARP table size on legacy devices. Make sure you are able to upgrade devices on your network if necessary.

[j-tadros]

Thank you for the helpful response. Can you please elaborate more on the routing and ARB tables size? 

[Flavio Miranda · Accepted solution]

Hi

 ARP table and routing table are tables used by device to store ARP entries and routing entries. If you increase the amount of network addressing in your environment not doing sumarization properly, you can end up out of space on your legacy devices.