MPLS Nooby

[Richard.Akers]

Hi,

Im currently designing a network for my final year university dissertation but i am having problems with the running/config of MPLS. My main quesrion is, is it possible to run mpls in the topology attached form Site 1 to site 2 through the service provider. All the examples i have read have the customer sites attached to separate routers within the service provider.

I have made the mistake of putting a fair bit of config on the topology already which is quite a bit larget than the example shown. If its not possible to do it this way it can be changed but is a fair bit or work with deadlines looming.

If anyone could point me in the right direction it would be a massive help.

Thanks

Rich

[Marcin Latosiewicz]

Rich,

Can you be a bit more specific on what you're trying to achieve?

For example if you want to create MPLS VPN yes can still use this topology (the other quiestion is if it makes sense or not, because you will not be able to remonstrate much apart from leaking routes).

However to fully simulate MPLS VPN you need:

(site1) CE router ----> PE router ----> P router ----> PE router ---> another CE router (site2)

Which is a more adequate representation of what would be going on in a real life scenario.

You can also built your own MPLS "backbone" by connecting site 1 and site 2  routers with a GRE tunnels (without any interaction from ISP).

For practical reasons I have never seen (maybe it does exists) that a ISP would allow you to talk MPLS with their network.

Marcin

[Atif Awan]

mlatosie wrote:
Rich,
Can you be a bit more specific on what you're trying to achieve?
For example if you want to create MPLS VPN yes can still use this topology (the other quiestion is if it makes sense or not, because you will not be able to remonstrate much apart from leaking routes).
However to fully simulate MPLS VPN you need:
(site1) CE router ----> PE router ----> P router ----> PE router ---> another CE router (site2)
Which is a more adequate representation of what would be going on in a real life scenario.
You can also built your own MPLS "backbone" by connecting site 1 and site 2  routers with a GRE tunnels (without any interaction from ISP).
For practical reasons I have never seen (maybe it does exists) that a ISP would allow you to talk MPLS with their network.
Marcin

Just to add to what Marcin said if you actually need to run true MPLS between your sites through the SP network you will need to do it over a tunneling mechanism. MPLSoGRE is a possible solution but it's support is platform dependent.

There is another implementation called CsC (Carrier Supporting Carrier) which can be used to exchange labels with SP via either LDP or BGP but it is not true MPLS between your sites connected to SP network.

If you explain what you are trying to achieve (as Marcin requested) we can probably guide you better.

Atif

[Richard.Akers]

Thanks so far lads.

Basicly The client is a small ISP that wants to provide layer 3 SLAs to its multi-site customers. Each multi-site customer wants the ability to securely move its traffic between sites through the ISPs network while running its own routing protocol. As the links through the ISP should be deemed private, address translation will not be used.

[Marcin Latosiewicz]

Rich,

If customers request provider service, MPLS VPN seems like the way to go here. Transparent to end customers and scalable.

The "security" concern might be a bit challanging.

In practice customers run either GETVPN on top of MPLS cloud.

Or deploy their own solution like DMVPN or GREoIPsec/VTI (depending on number of sites), which should be decently scalable/easy to deploy for end customers.

Marcin

[Richard.Akers]

Thanks again

Would u have any tips on how to configure mpls like this google doesnt seem to be too much of a help.

[Marcin Latosiewicz]

Rich,

Well there's no one place when you can start.

MPLS itself is quite easy to enable and works just great provided that IGP is working fine ;-)
Enabling MPLS on interface is as easy as doing "mpls ip".

Now for VPN deplyments I already assume you know your fair share of BGP, you should probably start here:

http://www.cisco.com/en/US/docs/ios/mpls/configuration/guide/mp_l3_vpn_roadmap_ps10591_TSD_Products_Configuration_Guide_Chapter.html

(there's also a section about L2 VPN)

Marcin