In this post we will be deploying an additional Edge Services Gateway (ESG) so that we can take advantage of Equal-Cost Multipath (ECMP) from the distributed logical router to the ESG. The advantage of using ECMP is that you can split the traffic from VMs evenly between the ESGs and have multiple bidirectional links. Let's get started configuring!
Navigate to Networking & Security > NSX Edges and click the green + to begin deploying a new ESG.
Enter a password and enable SSH access. Click Next.
On the Configure Interfaces page, click the green + to add a interface. We are going to configure our Uplink interface. Select type Uplink. Enter in a IP address and subnet prefix. Click Select.
Select the Production port group. Click OK.
Now let's create another interface to connect to our transit switch. This is done in the same way except we will be selecting our logical switch to connect to and not a port group. Enter a IP address and subnet prefix. Click Select.
Select the box next to Configure Default Gateway. Select the Uplink-Interface and enter in the IP address of the next hop switch/router. Click Next.
Now you must go and setup static or dynamic routing on this edge device. In this case I've configured OSPF on the edge devices, as you can see from the show ip ospf neighbor command below done on the edge device.
Now navigate to Networking & Security > NSX Edges and double click on the distributed logical router. Under Manage > Routing > Global Configuration click Enable next to ECMP. Publish the changes. Now we should be able to see a route pointing to both of our edge devices.
Open up the console on one of the edge devices and after logging in, enter show ip route. Notice we have a route going to the 172.20.10.0 and 172.20.11.0 networks for both of the edge devices. Now traffic will be able to be split between the two edge devices.
That's it! And just like that we've configured ECMP in our NSX environment.