with an ISP's network, is this how they configure a shared network for different customer, am i right in saying that MPLS does not split up customers networks on it's own, its just a quicker way of forwarding traffic?
MPLS/VPN is more of a service over MPLS (requires MPLS) and not MPLS itself.
So, its configuration involves more than just enabling MPLS.
The way forwarding is done in an MPLS core makes possible for the core routers
to afford to be ignorant about VPN routes (they consider top IGP label and
ignore VPN label in label stack). In this sense, MPLS forwarding mechanism assists
in the isolation, by not requiring VPN information to leak into the core.
It does need however other mechanisms to provide separation at the edge
to finally provide the MPLS/VPN service end-to-end.
MPLS/VPN uses routing (L3) information exchange to establish the connectivity between VPN sites. As such, it needs to manage the sharing of routes and that's the reason for the existence of VRFs at each PE. Each VRF keeps routes separated from routes of other VRFs and the Global Routing Table (separation at network edge). There exist administratively controlled mechanisms to exchange information between VRFs at various edges to achieve various topologies and business needs.
Although the benefits of MPLS are supposed to be numerous (MPLS TE is probably one of them), the forwarding acceleration benefit is often called the "bogus benefit", because the hardware chips used to perform Longest Prefix Match (LPM) lookups are now smart enough (compared to MPLS exact lookups, which were expected faster). In some cisco press book it says that the same chip does both lookup types in cisco equipment. This might need some discussion. Still, the point is that you cannot expect speedup when enabling MPLS.
MPLS doesn't provide real forwarding gain in modern routers because they have already developed route caching / switching methods (from the first Fast Switching to the current CEF and CEF distributed).
The real advantage of MPLS is the introduction of a forwarding plane and a signalling plane (made by LDP and the routing protocols in use) in the IP networks.
A provider can introduce IPv6 support in its network without requiring the inner core routers to support IPv6. (6PE and 6VPE solutions).
Only the PE routers are upgraded and reconfigured to support double stack IPv4 and IPv6: IPv6 packets are carried inside MPLS label frames with two level label stack : routers in the path to destination PE just swaps the external label.
In a IPv4 only network a router cannot forward a packet that it cannot route or even that it cannot recognize.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.