Is it possible to create l3vpn without enabling mpls in the core and PE routers .

Question

Hi 
i have below setup , in this PE1,P,PE2 routers do not have mpls support , it have only MGRE and GRE tunnel support ,
is it possible to create l3vpn without mpls here .
                          bgp session between PE1 and PE2, 
CE1---------------PE1-----------------P---------------PE2------------CE2 .
PE1,P,PE2 do not have mpls support .
Thanks
Duraipandi

Answer 1

hi durai,
you can use the vrf-lite model but this is complex to manage in larger networks.
for example:
CE1 ---PE----core(x)---P------PE---CE1
CE2  --/                                    \----CE2
in this case, without mpls, I need to create on the core(x) link 2 vrf's with 2 vlans to go to "P".
and the same on the other PE and link.
Now if you think that there are more P's with backup paths or more CE's that linkage exponentially increases to define those vlans and in all your P routers is that awareness of every CE route!
MPLS just simplifies this; single core link,by just using labels. Your P routers only see PE next hops and are opaque to the number of vrf's you carry/service. Adding another P or PE device integrates into the routing naturally and MP BGP takes care of the PE advertisement. So expanding and rerouting are more natural and graceful here too.
So while technically MPLS can be omitted, it is just not a smart thing to do from a design perspective in l3vpn.
cheers!
xander