MPLS-TE are not only applicable for VPNv4 prefix. Juniper has supported some features which are utilize LSP tunnel into Global routing domain instead of VRF.
This can be achieved by configuring LSP to include in the Global routing domain route processing. There are two approaches, using TE BGP IGP and TE shortcuts.
Here is the configuration of TE shortcut:
enugadi@aragorn# set protocols ospf traffic-engineering ?
Possible completions:
<[Enter]> Execute this command
— truncate—–
> shortcuts Use label-switched paths as next hops, if possible
Another approaches is under TE BGP IGP solution and I will give you simple explanation about that.
There are at least 3 application of MPLS-TE in Juniper router.
Number 1. TE BGP
Number 2. TE BGP-IGP
Number 3. TE BGP-IGP-BOTH-RIBS
enugadi@aragorn# set protocols mpls traffic-engineering ?
Possible completions:
bgp BGP destinations only
bgp-igp BGP and IGP destinations
bgp-igp-both-ribs BGP and IGP destinations with routes in both routing tables
mpls-forwarding Use MPLS routes for forwarding, not routing
Number one is Traffic engineering BGP which is turned by default. It means, BGP able to reach the destination using LSP tunnel in it available. In the MPLS architecture, only PE router has BGP session one another. VRF traffic between one PE router to another will use LSP as a next-hop. It will automatically exist without manual configuration.
Let’s move to the number 2. bgp-igp
The idea of TE BGP-IGP is moving all inet.3 tables to inet.0.
Table inet.3 will remain empty. Since table inet.0 have inet.3, BGP ipv4 native able to include inet.3 into their next-hop address. Yes, it’s LSP.
It’s usefully if you have only IPv4 protocols. Why only IPv4 ?
The answer is, since all routes in inet.3 moving to inet.0 this router will not capable to handle vpnv4. so, it applied only to IPv4.
Let’s move to number 3. bgp-igp-both-ribs
The idea of TE BGP-IGP-Both-ribs is moving all inet.3 table to inet.0. BUT, it will let table inet.3 still having RSVP/LDP prefix. With this method, VPNv4 service still supported.
Which one better? The answer is depends on your requirement. If you have only VPNv4, you don’t need to have neither BGP-IGP or Both-RIB. Just simply using BGP (number 1).
Personally, I used number 2 or 3 to handle traffic IBGP IPv4 native in Gateway, which is having full internet prefix.
