vHub SDWAn BGP (increase vHub Routing units)

Question

Hello All, When we deploy SDWAN NVA in the vHub is build 2 BGP with 2 routing units in Azure vHub
now we need to increase the capacity of vHub by increasing the routing units to 5
we did it and it is working
but i was under impression that extra BGP peers required ?
so i was expecting the SDWAN NVA will build 5 BGP peers ?
i cannot see any extra IPs in the vHub routing units to build BGP with
could you explain this to me, please.

Answer 1

Hi Zein, Responding questions:

• Does Increasing Routing Units Require Additional BGP Peers? No, increasing the number of routing units in an Azure Virtual WAN hub (vHub) does not necessarily require additional BGP (Border Gateway Protocol) peers. The BGP peering is established between the vHub and the Network Virtual Appliance (NVA), not on a per-routing-unit basis. This means that even when you increase the routing units, it doesn’t automatically mean that additional BGP peers will be created.
• Can the SDWAN NVA be expected to build 5 BGP peers? The SD-WAN NVA in an Azure Virtual WAN hub establishes BGP (Border Gateway Protocol) peering with the vHub, not on a per-routing-unit basis. So, while it’s possible for an SD-WAN NVA to build multiple BGP peers, it’s not directly tied to the number of routing units in the vHub. The number of BGP peers would depend more on your specific network design and requirements1.
• Why can't I see any additional IPs in the vhub routing units ? Can you elaborate a bit in this question?

Additional information:

• https://learn.microsoft.com/en-us/azure/virtual-wan/scenario-bgp-peering-hub
• https://learn.microsoft.com/en-us/azure/virtual-wan/hub-settings
• https://learn.microsoft.com/en-us/azure/virtual-wan/how-to-routing-policies

Let me know if this help you,

Luis