MPLS Layer 3 VPN PE-CE OSPF

Hi Laz,

Yes saw that aswell but in my GNS3 even when i am trying to do the command
redistribute ospf 2
its autmatically showing
redistribute ospf 2 vrf Customer
i am using image
c3725-adventerprisek9-mz124-15.image
Version 12.4(15)T7, RELEASE SOFTWARE (fc3)

is there some limitaions in gns3 i dont know

Hello Anoop

Hmm, as I said before, this doesn’t seem to be a problem, and since you tell me that the IOS puts it in there automatically, then you should be OK. In any case, your configs in your last post look good, and I don’t see an issue with the configurations. It could be a GNS3 problem. If you have the ability to do so, try employing this on CML or EVE-NG, or even on real devices if you can, just to see if we’re missing something or if it is indeed a GNS3 bug…

Let us know how you come along!

I hope this has been helpful!

Laz

image

Finally pinged in eve ng

CE11# ping 6.6.6.6 source lo0
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 6.6.6.6, timeout is 2 seconds:
Packet sent with a source address of 1.1.1.1 
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 13/20/24 ms
CE11#

PE1 end
PE1#sh bgp vpnv4 unicast vrf customerC
BGP table version is 7, local router ID is 2.2.2.2
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, 
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, 
              x best-external, a additional-path, c RIB-compressed, 
              t secondary path, 
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 2:2 (default for vrf customerC)
 *>   1.1.1.1/32       192.168.1.1              2         32768 ?
 *>i  6.6.6.6/32       5.5.5.5                  2    100      0 ?
 *>   192.168.1.0      0.0.0.0                  0         32768 ?
 *>i  192.168.5.0      5.5.5.5                  0    100      0 ?
PE1#sh ip route vrf customerC ospf    

Routing Table: customerC
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
       a - application route
       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is not set

      1.0.0.0/32 is subnetted, 1 subnets
O        1.1.1.1 [110/2] via 192.168.1.1, 00:05:34, GigabitEthernet0/0
PE1#

The only difference i made between gns3 and eve ng is that in eve ng both end i have defined vrf customerC
But in gns3 one end it was customer and other end it was Customer but with same RT value
dont think thats the issue though
so i guess its a gns3 issue may be

Hello Anoop

This is great, thanks for letting us know of your success in setting this up in EVE-NG!

VRF names are locally significant, so having one named “customer” and the other named “Customer” will make no difference. As long as the RT values are correct you’re good to go. So it looks like it was a GNS3 issue after all… Good work!

Thanks for sharing!

Laz

1 Like

easy to understand topic thanks again Rene

1 Like

Hi Rene,

Do you have something on multi- VPN- instance customer edge? Do we use the same RD for the PE and MCE?
Regards,

Hello Moven

What you are describing is called Multi-VRF CE according to Cisco. It allows a single CE device to terminate multiple VPNs enabling multiple customers to share the same physical link between the PE and CE, or a single customer to use multiple VPNs.

You can find out more information about this feature and how to configure it at the following Cisco documentation:

As can be seen from this documentation, within the same CE, you configure two different VRFs each of which has its own route distinguisher.

I hope this has been helpful!

Laz

Hi Lazaros,

Thank you so much. I have seen the documentation and went through it.

Regards,
Moven.

1 Like

Hi Laz,

Below configuration needs to be corrected because I tested it. I configured below without specifying the “vrf customer” after “router ospf” and it did not work. When I specified the “vrf customer” it all worked. I am using GNS3 in Dynamips mode Router 7200.

PE1 & PE2
(config)#router ospf 2
(config-router)#redistribute bgp 234 subnets

Also, please check the 2nd diagram in the lesson, it should be “CE” in Area 0 but it shows PE. Please correct this as well.

Thanks,
Rahul

Hello Rahul

Yes, you are correct, the command there should be as follows:

PE1 & PE2
(config)#router ospf 2 vrf CUSTOMER
(config-router)#redistribute bgp 234 subnets

Actually, if you look at the final configurations at the end, you will see that for PE1 that command is actually correct. I will let @ReneMolenaar know to make the correction in the lesson.

Thanks for pointing out the typo in the second diagram as well, I’ll pass it on to Rene.

Laz

Hi Rene,

I do not find any MPLS TE contants in networks.com website.

Could you please share the link for that?

Hello Costa

The truth is that there is little content on MPLS TE on the NetworkLessons site since this topic is not part of any of the Cisco certifications that are covered so far. In the meantime, you can find some useful links in this NetworkLessons note on the subject of MPLS traffic engineering.

If you would like to see this as a future topic on the site, take a look at the following Member Ideas page:

Here you can suggest the topics you would like to see, and you may find that others have already suggested this topic, so you can add your voice to theirs.

I hope this has been helpful!

Laz

where is the eBGP ?

i like your tutorials, please give me an answer .

Hello Mehdi

In this particular lesson, there is no eBGP being configured. This is because the topology has only one BGP AS, which is AS 234. The connections between the PE and CE routers are using OSPF to exchange routes, so there is no eBGP configured there.

In the context of MPLS L3 VPN, you will see eBGP peerings when the routing protocol used between the PE and CE routers is BGP. You can find an example of this in the following lesson, where eBGP is used as the routing protocol between the PE and CE routers:

I hope this has been helpful!

Laz

thank you for the reply .
i tried both methods together, but one is affection the other since the eBGP method has a command ‘’ no neighbor ‘’
how can i do them together ?
should i use different AS ( meaning the PE will have two AS numbers )

Hello Mehdi

When it comes to the configuration of MPLS Layer 3 VPN, you must choose a single method of exchanging routes between the CE and the PE. In the MPLS Layer 3 VPN Configuration lesson, for example, eBGP is used for this purpose.

Now, don’t confuse the peering between the PE and CE routers with the peerings within the MPLS core which are iBGP peerings within AS 234. The no neighbor command is used only within the IPv4 address family and only for the peerings between PE1 and PE3, not with the CE. Its purpose is to ensure that IPv4 routes will not be exchanged, but only VPNv4 routes will be exchanged, which is a different address family.

So if you want to create a topology where eBGP peerings exist between the CE and PE routers, just follow along in the MPLS Layer 3 VPN Configuration lesson and you should be OK. If you get stuck in something specific, let us know so we can help you out.

I hope this has been helpful!

Laz

it worked thanks for your good note(it was helpful), HOWEVER there is something else im struggling with .

im on the phase to try implement SR on the MPLS can you provide a basic SR configuration for CE1 and PE1 and P1 ?

i was going to ask you about implementing Qos on MPLS, i think i did it (my head-hurts from staying on laptop for so long )