[Enterprise SONiC] FRRouting and config initialization Follow

Tested model & firmware version:

• Switch model name:
  DCS203 (AS7362-56X)

• Edgecore SONiC version:
  202006.4
  202012.0 ~ 202012.4
  202111.0

Restriction: 

1. [Mandatory] FRR is an routing protocol suite for Linux platform.  It has other config files instead of /etc/sonic/config_db.json.  However, default config_db.json is incorrect and incomplete. Please refer to the following procedures to initialize FRRouting and config

Initialize FRR and config in the new version (After 202012.3)

Since 202012.3, Edgecore enhance Default configuration file with the command line, so users don't modify the config_db.json directly. (please refer to this article.)

After doing the reset to default with the command, the "docker_routing_config_mode" will be the "split", and here's the way to check it.

admin@SW1:~$ sudo show runningconfiguration all | jq .DEVICE_METADATA
{
  "localhost": {
    "buffer_model": "traditional",
    "default_bgp_status": "up",
    "default_pfcwd_status": "disable",
    "docker_routing_config_mode": "split",
    "frr_mgmt_framework_config": "true",
    "hostname": "SW1",
    "hwsku": "Accton-AS7326-56X",
    "mac": "04:f8:f8:6a:f6:91",
    "platform": "x86_64-accton_as7326_56x-r0",
    "synchronous_mode": "enable",
    "type": "LeafRouter"
  }
}

Initialize FRR and config (for Restriction #1)

Step 1:  Edit /etc/sonic/config_db.json

• Add // to comment out this object "BGP_NEIGHBOR": { }

• Add "docker_routing_config_mode": "split" to "DEVICE_METADATA" as shown below

• Remove the surplus setting  "bgp_asn": "65100"  from "DEVICE_METADATA", since "split" mode won't read BGP setting from /etc/sonic/config_db.json. 

{
    "//BGP_NEIGHBOR": {
        "10.0.0.1": {
            "asn": "65200",
            "holdtime": "180",
            "keepalive": "60",
            "local_addr": "10.0.0.0",
            "name": "ARISTA01T2",
            "nhopself": 0,
            "rrclient": 0
        },
        omitted...
    },
    omitted...
    "DEVICE_METADATA": {
        "localhost": {
            "bgp_asn": "65100",
            "buffer_model": "traditional",
            "default_bgp_status": "up",
            "default_pfcwd_status": "disable",
            "hostname": "sonic",
            "hwsku": "Accton-AS7326-56X",
            "mac": "04:f8:f8:6b:3e:91",
            "platform": "x86_64-accton_as7326_56x-r0",
            "type": "LeafRouter",
            "docker_routing_config_mode": "split"
        }
    },
   omitted...
}

Step 2. Reload config or power cycle the switch

admin@sonic:~$ sudo config reload -y

Step 3.  Verify the result

Check current configuration

admin@sonic:~$ show runningconfiguration bgp
Building configuration...

Current configuration:
!
frr version 8.0
frr defaults traditional
hostname sonic
zebra nexthop proto only
service integrated-vtysh-config
!
route-map RM_SET_SRC permit 10
set src 10.1.0.1
!
ip protocol bgp route-map RM_SET_SRC
!
line vty
!
end

Caution: If the result is failed, please go back to Step 1 and redo these steps.