Advice on MPLS

[liamelder]

I have a Uni project, there is 5 sites connecting to a central site but all sites must be able to communicate. I think MPLS is probably the best way to do this right?

Basically im wondering how MPLS products, such as BT's IP Clear, is delivered. How is it handed over, Ethernet? How do you address? And so on.

Thanks

[Latchum Naidu]

Hi,

I have the same kind of setup and the provider is Verizon.
All sites are connected over MPLS and site to site can directly communicate over mpls.
and the connection i have from PE routers is Ethernet handoff.

How is it handed over, Ethernet?
MPLS is mainly used to forward IP datagrams and Ethernet traffic

Please rate the helpfull posts.
Regards,
Naidu.

[Kimberly Adams]

Liam,

A lot of companies are going this direction with MPLS for their many sites to be able to communicate.  The company I am working for has an AT&T MPLS.  The basics of MPLS from a networking perspective is like ordering Internet T1's and you can have many bundled or they can see if Metro Ethernet is available depending on the bandwidth needs.  That is the WAN side and then it is handed to the Ethernet interfaces.  They will run BGP on the WAN side and distribute your network routing protocol into the BGP process.

On the provider side, there is a lot more configuration required but feels like an extension of the network.  The MPLS provider will setup protection and isolation of your WAN addresses.  The IP schemes are on the LAN can be private and on the WAN side usually public and provided by your provider.

I hope this helps and please rate the helpfull posts.

Thanks,

Kimberly

[liamelder]

Hi Kimberly thanks for your reply.

So I read you can use any speed of connection each office would prefer. Also

Some questions for you,

1. Can your traffic leave the MPLS setup for internet (browsing etc) purposes? Or would you have a seperate internet connection say at the head office, then route the general internet traffic of your users from the MPLS setup to the internet line?

2. I thought MPLS acted like a VPN? If it has public addressing how does node on site A connunicate with node on site B?

3. I know MPLS uses tagging, Is it your router that tags it before sending it on to the service provider, or do they tag it when they recieve it?

Thanks

[vmiller]

1. yes to both, that would be up to you and the provider to design out.

2. via labels. the simplest analogy would be "vlans for wans" .

3. Labels would be a more appropriate name I tend to reserve tagging for vlans.

Generally no, the Provider does all the heavy lifting.

Here is one of many links that explain how things work.

http://www.netcraftsmen.net/resources/archived-articles/373-bgp-and-mpls-based-vpns.html

[Kimberly Adams]

Liam,

You and the provider works out how you want the MPLS setup.  This company has their MPLS setup with basically 3 VLANS.  One VLAN for the main MPLS connection to the HQ, one VLAN for our Vendors with a DHCP range for basic Internet access, and the last VLAN for a Public routable Static IP for our manufacturers to have their connectivity to the Internet.  The bulk of the bandwidth is for the main connection to HQ and their are much smaller % for the other two internet connections.

When working with a provider to set this up, there are many ways to set it up.  You can take it a step further and have fully messed MPLS and partially messed.  This means you can have every location being able to communicate with every location or you can have certain locations that can talk to certain locations.

Thanks and I hope all this information helps.

Kimberly

[rupertsedgwick · Accepted solution]

hi

I use BT's MPLS ip clear

They manage the whole service and present as Ethernet. You can specify qos for voice too

I run our data vlans over dmvpn through the MPLS to detect failure and reroute traffic over a second DMVPN that uses the Internet.

HTH Rupert

Sent from Cisco Technical Support iPhone App

[liamelder]

Ok so as I understand.

I can ask BT to not let any traffic leave the cloud so that all internet bound traffic could be routed to Edinburgh before being alowed out on to a seperate internet connetion?

I can run this DMVPN on the cisco routers, Which will enable the remote routers to connect to the headquarters router meaning potentially DHCP can be run centrally there? IE cnetrally manage the network.

Am i getting this, site A host and site B host can both use private addresses (obviously) when site A host sents a packet To B it enters the Site A router which forwards it to the ISP router which tags it and forwards it to Site B? How does the ISP know where the site B host is?

How do you move the routing protocols updates etc around?  Using GRE tunnels?

Thanks

[rupertsedgwick]

Hi Liam

BT dont (as i recall) provide internet access as part of the IP Clear MPLS package so you'd need to create your own solution using an additonal internet service.

DMVPN uses eigrp and we use that for all of our dynamic routing, so it kind of takes care of itself. They're effectively GRE tunnels, so you can move protocols around at will.

You can use one sites connection to access the internet, you could achieve this with DMVPN or potentially by just asking BT to create a default route to your WAN router at Edinburgh.

All of this depends on what other routers etc and functionality you require at other sites.

We use DMVPN over the MPLS (without encryption) to give us the ability to transmit routing protocols as well as detect failure of the MPLS for a fast convergence to a backup VPN over the internet. If you have asked BT to provide voice QOS, you should keep the voice traffic out of the DMVPN tunnel (as we do) and use static routes accross the MPLS for the voice VLANs. Otherwise the MPLS wont be able to detect and prioritise the QOS markings.

DHCP can I think run over DMVPN, however we use a local server for that or the local router.

As a final note, typical delivery is 3 months / 60 working days. Any routing changes after delivery are chargeable. However DMVPN would negate the need for most changes too.

Rupert

PS you tell BT which subnets are at each site and they do the rest. It's transparent to you as a customer.

[liamelder]

Ive had a read up about DMVPN, why would you use that if you are on the MPLS service? The MPLS effectivally keeps you in a private network no?

Thanks