- need some more editing

The MPLS family requires to be activated on all the interfaces using MPLS traffic. Enter the [edit interfaces] mode to start configuring MPLS.

user@juniper> edit
user@juniper# edit interfaces

[edit interfaces]
user@juniper# set ge-0/0/0 unit 0 family mpls

[edit interfaces]
user@juniper# set fe-0/0/1 unit 0 family mpls

[edit interfaces]
user@juniper# show
  fe-0/0/1 {
   unit 0 {
     family inet {
      address 192.168.0.1/24;
     }
   family mpls;
   }
  }

  ge-0/0/0 {
   unit 0 {
    family inet {
     address 192.168.1.1/24;
    }
    family mpls;
   }
  }

[edit interfaces]
user@juniper# top

Protocol activation

Before MPLS can be implented in your network it must be explicitly be enabled under the [edit protocols] section.

[edit]
user@juniper# edit protocols

[edit protocols]
user@juniper# set mpls interface all

[edit protocols]
user@juniper# show
 mpls {
  interfaces all;
 }

[edit protocols]
user@juniper# commit

[edit]

Default labels

The example shows the default MPLS routing table. There are two labels, 0 and 1, created by JunOS. Label 0 is the IPv4 explicit NULL, and 1 is the router altert label.

[edit]
user@juniper# run show route table mpls.0

mpls.0: 2 destinations, 2 routers )2 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

0 *[MPLS/0] 00:05:12, metric 1 Receive
1 *[MPLS/1] 00:05:12, metric 1 Receive

[edit]

Static LSP (Labeled Switched Path) configuration

Unverified configuration example. I have not verified this example. The extracts are generated by changing IP's from a working setup. If somebody has a spare Juniper router; please verify the setup! If you plan to use this example on a production network read and study the MPLS protocol before attempting to configure the routers.

The folowing example will show a minimum configuration for a static LSP. We will create an MPLS connection between InterXion Paris and InterXion Brussels. Normall, an IGP (Interior Gateway Protocol) like OSPF (Open Shortest Path First) or IS-IS (Intermediate System-to-Intermediate System) would determine the path between Brussels and Paris. There is an label-switching router in Luxembourg to swap labels.

The first output shows Paris' routing table prior to the configuration of a static LSP. Notice that the prefered path is the IGP (OSPF)

user@paris> show route 192.168.0.1

inet.0: 10 destinations, 10 routes (9 active, 0 holddown, 1 hidden)
+ = Active Route, - = Last Active, * = Both

192.168.0.1/32 *[OSPF/10] 00:00:15, metric 20
> to 192.168.1.1 via fxp1.0

We will configure the static LSP from Paris through Luxembourg and reach the destination in Brussels. The example show the configuration used for Parix. In addition to adding the family mpls to all the required interfaces it's needed to add the static-path attribute to the configuration. This inserts a static route into the routing table for the address 192.168.0.1/32. Label 50 will be pushed on the packed destinated for 192.168.0.1/32. when they leave the LSR (Label Switching Router) for the next-hop 192.168.1.1

[edit protocols mpls]
user@paris# set static-path inet 192.168.0.1 next-hop 192.168.1.1 push 50

[edit protocols mpls]
user@paris# show
 static-path inet {
   192.168.0.1/32 {
    next-hop 192.168.1.1;
    push 50;
   }
  interface all;
 }

Since Luxembourg is a transit router, the only function it will serve is to swap the label. Label 50 is received from Parix and swapped with label 0, which will be sent to Brussels. When Brussels received the label 0 it will know to pop the label and route the packed like normal Ipv4 traffic.

[edit protocols mpls]
user@luxembourg# set interface ge-0/0/0 label-map 50 next-hop 192.168.3.1 swap 0

[edit protocols mpls]
user@luxembourg# show
 interface all;
 interface ge-0/0/0.0 {
  label-map 50 {
   next-hop 192.168.3.1;
   swap 0;
  }
 }

We now have a fully working static LSP path. When we look at the route again, we shall see the new labeled path.

user@paris> show route 192.168.0.1

inet.0: 11 destinations, 11 routes (10 active, 0 holddown, 1 hidden)
+ = Active Route, - = Last Active, * = Both

192.168.0.1/32 *[Static/5] 19:52:42
> to 192.168.1.1 via fxp1.0, Push 50
*[OSPF/10] 19:52:43, metric 20
> to 192.168.1.1 via fxp1.0