Announce routes to the exabgp processes running in the PTF container.
This method is automatically run in add-topo period or manually run from localhost. (Related api doc: announce_routes.md).
In this method, we generate routes for different topos by configuration defined in ansible/vars/topo_*.yml files.
Get the configuration of all neighbor VMs, and use different rules to generate routes according to the router type of the neighbor. Then send post requests to the exabgp processes running in the PTF container to announce routes to DUT.
| topo type | upstream router type | downstream router type |
|---|---|---|
| t0 | leaf | N/A |
| t1 | spine | tor |
| t2 | core | leaf |
| t0-mclag | leaf | N/A |
| m0 | m1 | mx |
For M0, we have 2 sets of routes that we are going to advertise:
- 1st set routes are advertised by the upstream VMs (M1 devices).
- 2nd set routes are advertised by the downstream VMs (MX devices).
The picture below shows how the routes is announces to DUT. The green arrows indicate routes that announced by upstream M1. The blue arrows indicate routes that announced by downstream MX. The yellow line indicates subnets that directly connected to DUT, which need to be skipped when generating routes.
Some definitions:
| definition | description |
|---|---|
| colo | cluster of M0 devices |
| colo_number | number of COLOs |
| m0_number | number of subnet in a M0 |
| m0_subnet_number | number of members in a M0 subnet |
| mx_number | number of MXs connected to a M0 |
| mx_subnet_number | number of members in a MX subnet |
The total number of routes are controlled by the colo_number, m0_number, mx_subnet_number, m0_subnet_number and number of MX devices from the topology file. We would have the following distribution:
- Routes announced by per M1 device, total number: 1 + 1 + (colo_number * m0_number - 1) * (m0_subnet_number + mx_number * mx_subnet_number)
- 1 default route, prefix: 0.0.0.0/0.
- 1 loopback route.
- Subnet routes of M0 devices connected to M1 devices other than directly connected to DUT, count: (colo_number * m0_number - 1) * m0_subnet_number.
- Subnet routes of MX devices connected to M0 devices connected M1 devices, count: (colo_number * m0_number - 1) * mx_number * mx_subnet_number.
- Routes announced by per MX routes, total number: 1 + mx_subnet_number
- 1 loopback route.
- Subunet routes of MX, count: mx_subnet_number.