O'Reilly logo

Junos Security by James Quinn, Timothy Eberhard, Patricio Giecco, Brad Woodberg, Rob Cameron

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Routing Instances

This and the next section (Filter-Based Forwarding) will move beyond the more customary IP routing topics to some of what makes IP routing in the Junos operating system so unique.

The Junos control plane is far more versatile than that of a typical IP router. Junos is not limited to one monolithic routing table, but rather can support hundreds and even thousands of distinct routing tables on the highest-end platforms.

Likewise, the Junos data plane is not restricted by traditional destination-based routing when making forwarding decisions (as you’ll explore in both this and the next section). It can make forwarding decisions based on nearly any relevant fields in the Layer 3 and Layer 4 headers.

The power and flexibility that is put in your hands by this combination of highly unique control plane and equally unique data plane is extraordinary. In an age when virtualization has become a buzzword, IP routing in Junos is the real deal. You will scratch the surface of Junos’s power in the following sections.

Configuring Routing Instances

The routing-instance is the basic building block for constructing the multiplicity of custom routing tables, forwarding entries, and routing protocol instantiations that are possible with the Junos operating system.

In the Junos CLI configuration that follows, you will create a custom routing-instance with its own routing table, interface, and OSPF, as depicted in Figure 11-11.

Figure 11-11. Routing instances

Here you enter configuration mode ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required