Layer 3 Gateway - VXLAN Routing

The problem with Trident 2 is that it doesn't route VXLAN.

which means in simple language that if we have a VLAN and we have a VTEP interface assigned to the same VLAN, we cannot have a SVI (Layer 3 interface on VLAN). So no routing, no ping, no ARP on the VLAN.

The solution to solve this issue is to somehow connect this VLAN to another Router. this router can be the switch itself or an external device, or even a Virtual router.

There is a method explained in LNV document to connect 2 ports of the switch. One port from the VLAN which has a VTEP (for example VLAN 15) and another port as a Layer 3 port (direct IP on the interface). With this solution we can provide routing to 1 VXLAN, and if we need to enable routing for more VXLANs, we need to connect more cables and create the same topology for other VXLAN.

Converting this port to a 802.1Q tagged port on both sides will create a loop and doesnt work.

What could be a good solution for VXLAN routing when we have multiple VXLANs?

I was thinking about using a Spine as external router and expand all the leaf VLANs to the Spin. but its a ugly solution.

2 replies

The recently released Trident-II+ chip provides native VXLAN routing and you should be seeing switch manufactures start rolling them out later this year. I'm not able to replace all my leaf switches at once, but I do plan on replacing the switches I'm currently using to connect back into our "legacy" network when the Trident-II+ switches are released. Sorry that doesn't solve your immediate need but it's good to know a more integrated solution is on the horizon.
Hi Richard

yes, Im also counting for T2+ , both Trident 2+ and Tomahawk support this feature. But Trident II+ is sampling now and probably we will see new switches next year. Tomahawk probably available by end of year, but seems to be overkill and expensive as a leaf.

How do you connect back to your legacy network for routing? have you extended the vlans back to a L3 switch and perform routing there ?

I'm also searching for solution at the host level or virtual switch level to perform the routing at host level.