Interface basics on the Juniper MX
I’ve been spending more time on the MX recently and I thought it would be worthwhile to document some of the basics around interface configuration. If you’re like me, and come from more of a Cisco background, some of configuration options when working with the MX weren’t as intuitive. In this post, I want to walk through the bare bone basic of configuring interfaces on a MX router.
Basic L3 interface
ge-0/0/0 { unit 0 { family inet { address 10.20.20.16/24; } } }
The most basic interface configuration possible is a simple routed interface. You’ll note that the interface address is configured under a unit
. To understand what a unit is you need to understand some basic terminology that Juniper uses. Juniper describes a physical interface as an IFD (Interface Device). In our example above the IFD would be the physical interface ge-0/0/0
. We can then layer one or more IFL (Interface Logical) on top of the IFD. In our example the IFL would be the unit configuration, in this case ge-0/0/0.0
. Depending on the configuration of the IFD you may be able to provision additional units. These additional units (Logical interfaces (IFLs)) Continue reading