Routing on MPLS network

nitish-gupta · ‎09-17-2015

I am having an scenario in which my router is connecting to ISP router with 1 Gig link, and we are running all the services over that link. Recently we have come with one more new link on that routers making the capacity as 1G + 1G. We do not want to aggregate both the links, instead we want to run MPLS on the new link and on the older one we want to run BGP. So please suggest

1. Is it feasible to MPLS on the ISP link, as that further require an LDP and that further requires an IGP.

2. We want to run BGP on both the links in same AS.

3. We want to define the VRFs.

4. We want to run both links in active/standby scenario, when new link fails (on which we want to run MPLS) then the traffic shifts to the older one.

Please suggest any solution in which above requirements can be met.

Nagendra Kumar Nainar · ‎09-17-2015

Hi Nitish,

Can you help us better understand your requirement?. From the post, I understand that you want to use the new circuit as primary egress and if it fails, you want to use the old circuit. Since they both are terminating on same ISP router, you can achieve this with floating (default) static route itself.

Can you help understand why you need to define VRF in your router?. Do you intent to make this router as a kind of PE to provide VPN service to end customer/department?.

Also why do you need to enable MPLS on the new circuit?. Is it a requirement from your ISP?.

Thanks,

Nagendra

nitish-gupta · ‎09-17-2015

Thanks Nagredra for your reply.

If i use static floating route, that will be fine for the outbound traffic. For the incoming traffic i have some public ips that i am advertising in bgp to my ISP. So for that ISP will not agree to run static routing for my inbound traffic.

Can you help understand why you need to define VRF in your router?. Do you intent to make this router as a kind of PE to provide VPN service to end customer/department?. Yes, actually my aim is to run either some VPLS or L2 IPLC services for few end users. Can you help me to suggest on L2 VPN can run over MPLS or not, and please suggest how to actually design that.

Also why do you need to enable MPLS on the new circuit?. Is it a requirement from your ISP?.Its just for L2 IPLC and even i do not find any use of running MPLS on a single Point to point link. Please correct me if i wrong.

So in whole i ll explain my requirement again.

I am having a new link to my ISP on the same routers on which old one is running. Once the link is there we are planning to run L2 IPLC on that, so for that we are planning or thinking of running VPLS. So please help me, if still any doubt please tell will try to explain again.

pedroangeldiaz · ‎09-17-2015

Hi Nitish,

Often (depend of the scenario) the best option for layer 3 CE-PE (you and your ISP) communication is BGP, so you can play with BGP attributes to load-balance inbound and/or outbound; usually the ISP run MPLS internally, no with the customers.

If you want a to create VPLS with MPLS, you need to run MPLS in your devices. Hope the link below help you:

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/mp_l2_vpns/configuration/xe-3s/mp-l2-vpns-xe-3s-book/mp-vpls.html

nitish-gupta · ‎09-18-2015

Thanks pedroangeldiaz and Nagendra.

I have just tested one Frame relay over MPLS solution in GNS3 as of now. It was working over that. But i do have some doubts.

1. Will that run as my router and isp router are in different AS.

2. Frame relay over MPLS hardware requirement.

3. Does its feasible to run MPLS over a point-to-point link even if the ISP agrees.

4. Instead of having frame relay over MPLS, can i go for frame relay only with BGP. Still having the L2 functions.

Nagendra Kumar Nainar · ‎09-17-2015

Hi Nitish,

If i use static floating route, that will be fine for the outbound traffic. For the incoming traffic i have some public ips that i am advertising in bgp to my ISP. So for that ISP will not agree to run static routing for my inbound traffic.

<Nagendra> Like Pedro mentioned, you could use BGP for both inbound and outbound traffic control. You can advertise the internal prefixes and manipulate metric/AS-PATH attribute to control the inbound traffic. On the same line, you can either receive default route from your ISP neighbors or just use floating static in your router. If the requirement is just to use one circuit as primary and other secondary, this will help.

Can you help understand why you need to define VRF in your router?. Do you intent to make this router as a kind of PE to provide VPN service to end customer/department?. Yes, actually my aim is to run either some VPLS or L2 IPLC services for few end users. Can you help me to suggest on L2 VPN can run over MPLS or not, and please suggest how to actually design that.

<Nagendra> Ok. In order to run L2VPN, you may need to enable MPLS on R1 interfaces connecting to ISP (which in turn requires the same to be enabled on R2 as well). The other alternate is to enable L2TPv3 and extend your LAN over IP cloud.

Also why do you need to enable MPLS on the new circuit?. Is it a requirement from your ISP?.Its just for L2 IPLC and even i do not find any use of running MPLS on a single Point to point link. Please correct me if i wrong.

<Nagendra> If you have a business need to extend your LAN over IP cloud, you either need MPLS to enabled and use L2VC or use L2TPv3. If you plan to run VPLS, you may need to check the HW support as well.

So in whole i ll explain my requirement again.

I am having a new link to my ISP on the same routers on which old one is running. Once the link is there we are planning to run L2 IPLC on that, so for that we are planning or thinking of running VPLS. So please help me, if still any doubt please tell will try to explain again.

<Nagendra> Hope the above helps.

-Nagendra