xconnect is up on both side but not working via different VLANs

[alexals]

Hi there,

I set up a lab recently to test EoMPLS via MPLS network. I set up xconnect configuration on both side and the link status shows 'UP". But I'm unable to get a my machine to link on each other via EoMPLS as both are on different VLANs. I'm using two Cisco ISR1921 which each connected to two Cat3550 switch via VLAN trunk. Both my machines are on VLAN 100 and VLAN 400.

Is there a way to overcome this or ... this is only supported in latest version of IOS and/or hardware?

Thank you for your advice

Alex

p/s: apologize for my bad grammar.

[Julio E. Moisa]

Hi

Could you please share your configuration and show xconnect all outputs? If you are going to use EoMPLS both VC should be same ID and the ends under the same vlan. 

Thank you in advance. 

[alexals]

Hi Julio,

Here both configuration for xconnect on different VLAN and router:

PE01 router

!
interface GigabitEthernet0/1.2
 description CUSTOMER-P2P_L2VPN
 encapsulation dot1Q 201
 xconnect 10.255.254.1 1001 encapsulation mpls
!

----------------------------------------------------------------------------------------------------------------------------------

PE02 router

!
interface GigabitEthernet0/1.3
 description CUSTOMER-P2P_L2VPN
 encapsulation dot1Q 302
 xconnect 10.255.255.1 1001 encapsulation mpls
!

Attached is the network diagram that explains the set up.

Thanks in advance

Regards,

Alex

[Julio E. Moisa]

Hi

The VC ID should be the same, and the VLAN as well, as you are creating a layer 2 point to point they should be under the same network otherwise the xconnect will be displayed as Up -  Down on each end.

PE01 router

!
interface GigabitEthernet0/1.2
 description CUSTOMER-P2P_L2VPN
 encapsulation dot1Q 201
 xconnect 10.255.254.1 1001 encapsulation mpls
!

----------------------------------------------------------------------------------------------------------------------------------

PE02 router

!
interface GigabitEthernet0/1.2
 description CUSTOMER-P2P_L2VPN
 encapsulation dot1Q 201
 xconnect 10.255.254.2 1001 encapsulation mpls
!

:-)

[alexals]

Hi Julio,

Thank you for your fast response. Does it mean that whatever set up on PE01 router for xconnect should be EXACTLY the same for PE02 router as well? I'm curious on the IP address for both PE01 and PE02 router: do you mean it should be the same? 

Regards,

Alex

[Julio E. Moisa]

Hi

You are welcome  :-)

No, the IP address on each PE must be under the same network segment, for example if the vlan10 is associated to the network 192.168.10.0/24, the PE01 could has the IP .1 and the PE02 the IP .150

EoMPLS is used to create a layer 2 connection between 2 devices and after that you can pass traffic over that virtual circuit.  You could have multiple xconnect VC under the same interface using sub-interfaces associated to VLANs. 

:-)

[alexals]

Hi Julio,

The IP addresses referring to the loopback of PE01 and PE02 router. For example,

PE01 - 10.255.255.1

PE02 - 10.255.254.1

From what I understood, the ip address for xconnect on both router are pointing to each other with same VC ID. 

Kindly enlighten me :-)

Alex

[Julio E. Moisa]

Hi

No worries my friend, 

If your network segment is 10.255.254.0/23

You can use: 

PE01: 10.255.255.1

PE02: 10.255.254.1 

Because they are part of the valid IP addresses into the network segment /23

10.255.254.0/23

Subnet mask: 255.255.254.0

And the valid IP address range is.  10.255.254.1 to 10.255.255.254

Now if you are using 2 different subnets with mask /24 it will no allow you to create the EoMPLS

:-)

[alexals]

Hi Julio,

I forgot to mention earlier that those IP addresses are actually the loopback IPs using /32 (255.255.255.255) masks.

Thanks.

Alex

[Julio E. Moisa]

Thank you Alex, 

Just correct me, are these IP addresses the loopbacks or an IP advertised by the IGP used for the LDP on each PE?  Apologies I was seeing them from other perspective, my fault. 

If you have communication between these IP addresses the xconnect should go up up.  Now the sub-interface must have the same ID and VLAN.

PE01 router

!
interface GigabitEthernet0/1.2
 description CUSTOMER-P2P_L2VPN
 encapsulation dot1Q 201
 xconnect 10.255.254.1 1001 encapsulation mpls
!

PE02 router

!
interface GigabitEthernet0/1.2  <--- It should have the same like PE01
 description CUSTOMER-P2P_L2VPN
 encapsulation dot1Q 201
 xconnect 10.255.255.1 1001 encapsulation mpls

Can you ping each other IP?

[Julio E. Moisa]

It should fix the communication. 

:-)

[alexals]

Hi Julio,

Attached the results of xconnect for PE01 and PE02 for your attention. I did not change any configuration as what you had suggested. This is based on my current working configuration.

I think you are right in the sense of the VLAN should be the same on both ends as it is a L2 link.

Let me know your opinion about this.

Alex