The JUNOS software architecture is designed to be highly scalable, secure, and flexible, allowing network administrators to build and manage large, complex networks with ease. The modular design of the JUNOS software allows administrators to add new features and functionality without impacting the existing functionality of the system. Additionally, the JUNOS software provides a robust set of management and monitoring tools, making it easier to manage, troubleshoot, and maintain large and complex networks.
Control and forwarding planes
The control plane and forwarding plane are two distinct functional components of a network device, such as a router or switch.
The control plane is responsible for managing the network's routing and forwarding tables, determining the best path for incoming data, and managing the device's configuration and behavior. This includes tasks such as running routing protocols, processing firewall policies, and performing other control-plane functions.
The forwarding plane is responsible for forwarding data packets between network interfaces based on the information in the routing and forwarding tables. This includes tasks such as forwarding packets based on their destination addresses, applying Quality of Service (QoS) policies, and performing other data-plane functions.
The separation of the control and forwarding planes allows network devices to perform these functions independently and in parallel, providing efficient and scalable operation. This also allows the control plane to be isolated from the forwarding plane, improving security and resilience against attacks on the network.
JUNOS Transit traffic processing
JUNOS transit traffic refers to the data packets that are forwarded through a network device, such as a Juniper router, as they travel from their source to their destination.
In JUNOS, transit traffic is processed by the Forwarding Engine (FE) component of the JUNOS software architecture. The FE is responsible for the data-plane functions of the JUNOS software and is responsible for forwarding transit traffic through the network device.
When a packet arrives at the device, the FE performs a lookup in the routing and forwarding tables to determine the best path for the packet. If a route is found, the FE will forward the packet to the next hop in the network. If a route is not found, the packet will be dropped.
In addition to forwarding transit traffic, the FE can also perform other data-plane functions, such as Quality of Service (QoS) management, traffic shaping, and rate limiting. These functions can be used to control and manage transit traffic as it passes through the network device.
Overall, JUNOS transit traffic processing provides a scalable and efficient way to forward transit traffic through a network, allowing administrators to build and operate large and complex networks with ease.