ASR1000: Cisco Vxlan Multicast Mode Configuration and Verification

 

DCI (Date Center interconnect) :  DCI is a very special technology for which almost all the big players now have at least one solution, and the best part is that it was not available just few years ago. In my earlier Blogs I have written a little about Avaya SPBM which is also a data center interconnect and a part from this there are others and most famous ones are OTV(Overlay transport virtualization) and VxLAN(Virtual Extensible LAN). I am going to discuss Vxlan specifically in this Blog.

Following are few of the Terminology for this protocol.

VNI (Vxlan Network Identifier) – 24 bit segment ID that defines the broadcast domain. Interchangeable with “VXLAN Segment ID”.

VTEP (Virtual Tunnel Endpoint) – This is the device that does the encapsulation and de-encapsulation.

NVE (Network Virtual Interface) – Logical interface where the encapsulation and de-encapsulation occur.

The best part about these DCIs is that they transport independent. That means you can use the same ISP connectivity or whatever you have been using to connect your sites earlier like MPLS etc and any DCI protocol would work over it. Its similar to Cisco GRE which also works on any kind of transport between the sites.

In our configuration as well  you do not need to worry about the transport part. You just need to ensure that transport is unicast and multicast enabled.

Following is the network diag :

 

Cisco Vxlan ASR1000 Multicast mode
VxLAN Multicast mode

 

In this example we will keep it simple and try to extend just untagged traffics hitting LAN interface of the router.

Configuration :

ASR1000-LeftRoter(VTEP1) :
!
Vxlan udp port 1024
!
Interface Loopback1
ip address 1.1.1.1 255.255.255.255
ip pim sparse-mode
!
Defining the VNI members and the member interface under bridge-domain configuration.
!
bridge-domain 1
member vni 6001
member Gig0/1 service-instance 1
!
Creating NVE(network virtual interface) and define the VNI members which needs to be extended over the WAN to other data centres.
!
interface nve1
no ip address
member vni 6001 mcast-group 239.0.0.10
source-interface Loopback1
!
Creating service instances over the LAN interface (interface connects the LAN network) to overlay the particular Vlan(802.1q tagged
!
interface Gig0/1
no ip address
no shut
!
Need to remove the vlan tag before sending the traffic across overlay and also need to push it once the return traffic is being sent into the vlan.
!
service instance 1 ethernet
encapsulation unagged

 

ASR1000-RightRouter(VTEP2) :

Vxlan udp port 1024
!
interface Loopback1
ip address 2.2.2.2 255.255.255.255
ip pim sparse-mode
!
!
bridge-domain 1
member vni 6001
member Gi0/1 service-instance 1
!
!
interface nve1
no ip address
member vni 6001 mcast-group 239.0.0.10
source-interface Loopback1
no shut
!
!
interface gig0/1
no ip address
cdp enable
service instance 1 ethernet
encapsulation untagged

This is all from configuration point of view between the VTEPs. You need to install a host in the LAN both at both sites to check the connectivity. As I discussed earlier that the core network needs to be multicast enabled so it is always better to verify the multicast core with the help of any multicast tool. In case there is no tool available you may try following :

Configure loopback at one side to join any multicast group, 239.0.0.10 in this case and ping this from other side of the network. You should see the response coming in which validates the multicast core over which Vxlan multicast mode should work.

VTEP1(config)#int loopback1
VTEP1(config-if)#ip igmp join-group 239.0.0.10

 

We can use following Verification commands to check the status.

Router# show nve vni
Router#show nve vni interface nve1
Router#show nve interface nve1
Router#show nve interface nve1 detail
Router#show nve peers

 

Thank You for visiting my blog. Please leave your questions and suggestion in the comment section. I would love to hear from you.

Stay Tuned for more.


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