- Why I did it
MSN4700 platform has 8 lanes per port and thus can support 2x40G with each lane running at 10G
- How I did it
Added 40G to 2x200G breakout mode in platform.json
- How to verify it
Run config int break Ethernet0 2x40G[200G,100G,50G,25G,10G,1G]
And verify the command runs successfully and the port speed was set to 40G with a 2x breakout.
#### Why I did it
Current platform.json lacks some peripheral device related facts, like chassis/fan/pasu/drawer/thermal/components names, numbers, etc.
#### How I did it
Add platform device facts to the platform.json file
Signed-off-by: Kebo Liu <kebol@nvidia.com>
To fix [DPB| wrong aliases for interfaces](https://github.com/Azure/sonic-buildimage/issues/6024) issue, implimented flexible alias support [design doc](https://github.com/Azure/SONiC/pull/749)
> [[dpb|config] Fix the validation logic of breakout mode](https://github.com/Azure/sonic-utilities/pull/1440) depends on this
#### How I did it
1. Removed `"alias_at_lanes"` from port-configuration file(i.e. platfrom.json)
2. Added dictionary to "breakout_modes" values. This defines the breakout modes available on the platform for this parent port, and it maps to the alias list. The alias list presents the alias names for individual ports in order under this breakout mode.
```
{
"interfaces": {
"Ethernet0": {
"index": "1,1,1,1",
"lanes": "0,1,2,3",
"breakout_modes": {
"1x100G[40G]": ["Eth1"],
"2x50G": ["Eth1/1", "Eth1/2"],
"4x25G[10G]": ["Eth1/1", "Eth1/2", "Eth1/3", "Eth1/4"],
"2x25G(2)+1x50G(2)": ["Eth1/1", "Eth1/2", "Eth1/3"],
"1x50G(2)+2x25G(2)": ["Eth1/1", "Eth1/2", "Eth1/3"]
}
}
}
```
#### How to verify it
`config interface breakout`
Signed-off-by: Sangita Maity <samaity@linkedin.com>
