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 :
In this example we will keep it simple and try to extend just untagged traffics hitting LAN interface of the router.
ASR1000-LeftRoter(VTEP1) : ! Vxlan udp port 1024 ! Interface Loopback1 ip address 184.108.40.206 255.255.255.255 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 220.127.116.11 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 18.104.22.168 255.255.255.255 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 22.214.171.124 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, 126.96.36.199 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 188.8.131.52
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
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