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OSPF Unsupported?

Could someone clarify whether OSPF is supported on the CSR100V in AWS?


Pg 14 of this document says no


Pg 9 of this Doc describes Running OSPF with DMVPN, which is what I want to implement



Cisco Employee

StayinFront107,The reason


The reason that OSPF (and some other protocols) are not supported within AWS is the lack of support for multicasts and broadcasts (see Amazon AWS FAQ).  Unfortunately this behavior effectively disables many LAN protocols that rely on broadcasts and multicasts to function properly.  With that said, one way to workaround this is to tunnel the traffic across the AWS infrastructure.  For example, the use of a GRE tunnel entirely within AWS, but terminating on another CSR on a GRE tunnel.  Page 9 in the document you reference discusses running OSPF over the DMVPN tunnel back toward a hub, this will also work as it is being tunneled out of AWS and does not require that AWS support multicast traffic because it is encapsulated in a tunnel.  The issue is not support of the feature within the CSR, as the CSR installed in AWS is the same CSR installed on your own hardware, the same features can be configured.  The problem is that the underlying infrastructure inhibits these particular types of traffic and therefore breaks the protocol if it is riding directly on top of the AWS "LAN" segment.

Hope that helps,



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