Junos OS Basics
• Robust
• Modular
• Scalable
Based on FreeBSD Kernel
Planes
1. Control Plane
2. Forwarding OR Data plane
Control Plane – controls routing and switching, consists of the Routing Engine (RE)
Data Plane – forwards frames, packets etc, consists of the Packet Forwarding Engine (PFE)
These two planes combined give Junos:
1. Reliability
2. Performance
Routing Engine (RE)
1. Routing tables
2. Bridging tables
3. Primary forwarding table
RE connects to the PFE via internal link
Packet forwarding engine (PFE)
1. Rate limiting
2. CoS
3. Stateless filtering for firewalls
HA features
1. GRES – Graceful Routing Engine Switchover
2. NSR – Nonstop Active Routing
3. ISSU – In-Service Software Upgrades
Transit Traffic
ALL Traffic coming in to Ingress port
EXCEPTION Traffic
Ping, Telnet, Traceroute etc