According to RFC 1812, to which layer do OSPF and BGP belong, Application or Internet Layer? To your surprise, the answer is the Application layer.
TCP/IP Model
It depends on the model you are following. RFC 1812 apparently stands for the TCP/IP model. OSPF and BGP belong to the Application Layer.
Routing Protocols in Application Laye
ISO Model
From the perspective of ISO 7498-1, the OSI Basic Reference Model, it is generally accepted that they belong to the Network Layer.
7.5.2.4 Any relay functions and hop-by-hop service enhancement protocols used to support the network-service between the OSI end systems are operating below the Transport Layer, i.e. within the Network Layer or below.
Source: ISO 7498-1
Hi there,
I don’t think there is any confusion around your question. Routing protocol are control plane functions and are obviously applications. The services (from OSI model) you’re pointing to above are data plane services that each layer is providing to the layer above it to route the frame/packet to the next hope/destination.