Table of Contents

Configuring the interface breakout mode (Dynamic Port Breakout)

Configuring the interface breakout mode (without Dynamic Port Breakout)

Configuring the interface breakout mode (Dynamic Port Breakout)

Example model & SONiC version (with Dynamic Port breakout support):

• Aurora 830, Aurora 721, Aurora 621
• Netberg SONiC: sonic-broadcom-202311.n0

NOTE:

• Admin status of interfaces is down by default after applying the Dynamic Port Breakout setting.
• Aurora 621 only supports two breakouts on ports Ethernet64, and Ethernet68.

Pre-requisite:

1. The port must not participate in VLANs.
2. The port should not have an IP address.
3. The port should not be a member of a LAG.

Broadcom Trident-enabled switches support the Dynamic Port Breakout function in SONiC.

Check the breakout availability and syntax:

admin@sonic:~$ show interfaces breakout
...
   "Ethernet124": {
       "index": "31,31,31,31",
       "lanes": "121,122,123,124",
       "breakout_modes": {
           "1x100G[40G]": [
               "Eth31(Port31)"
           ],
           "2x50G": [
               "Eth31/1(Port31)",
               "Eth31/2(Port31)"
           ],
           "4x25G": [
               "Eth31/1(Port31)",
               "Eth31/2(Port31)",
               "Eth31/3(Port31)",
               "Eth31/4(Port31)"
           ],
           "4x10G": [
               "Eth31/1(Port31)",
               "Eth31/2(Port31)",
               "Eth31/3(Port31)",
               "Eth31/4(Port31)"
           ]
       },
       "default_brkout_mode": "1x100G[40G]",
       "Current Breakout Mode": "1x100G[40G]",
       "child ports": "Ethernet124",
       "child port speeds": "100G"
   }

We will split 100G port 124 into four 10G ports.

Check the port status:

admin@sonic:~$ show interfaces status
  Interface            Lanes    Speed    MTU    FEC            Alias    Vlan    Oper    Admin             Type    Asym PFC
-----------  ---------------  -------  -----  -----  ---------------  ------  ------  -------  ---------------  ----------
Ethernet120  125,126,127,128     100G   9100    N/A    Eth30(Port30)  routed    down       up              N/A         N/A
Ethernet124  121,122,123,124     100G   9100    N/A    Eth31(Port31)  routed    down       up  QSFP28 or later         N/A
Ethernet128              129      10G   9100    N/A    Eth32(Port32)  routed    down       up              N/A         N/A

Use the DPB configuration command on the port:

admin@sonic:~$ sudo config interface breakout Ethernet124 '4x10G'
Do you want to Breakout the port, continue? [y/N]: y
Running Breakout Mode : 1x100G[40G]
Target Breakout Mode : 4x10G
Ports to be deleted :
 {
    "Ethernet124": "100000"
 }
Ports to be added :
 {
    "Ethernet124": "10000",
    "Ethernet125": "10000",
    "Ethernet126": "10000",
    "Ethernet127": "10000"
}
Breakout process got successfully completed.
Please note loaded setting will be lost after system reboot. To preserve setting, run `config save`.
admin@sonic:~$ sudo  config save -y
Running command: /usr/local/bin/sonic-cfggen -d --print-data > /etc/sonic/config_db.json

Check the result:

admin@sonic:~$ show interfaces status
  Interface            Lanes    Speed    MTU    FEC            Alias    Vlan    Oper    Admin             Type    Asym PFC
-----------  ---------------  -------  -----  -----  ---------------  ------  ------  -------  ---------------  ----------
Ethernet120  125,126,127,128     100G   9100    N/A    Eth30(Port30)  routed    down       up              N/A         N/A
Ethernet124              121      10G   9100    N/A  Eth31/1(Port31)  routed    down     down  QSFP28 or later         N/A
Ethernet125              122      10G   9100    N/A  Eth31/2(Port31)  routed    down     down  QSFP28 or later         N/A
Ethernet126              123      10G   9100    N/A  Eth31/3(Port31)  routed    down     down  QSFP28 or later         N/A
Ethernet127              124      10G   9100    N/A  Eth31/4(Port31)  routed    down     down  QSFP28 or later         N/A
Ethernet128              129      10G   9100    N/A    Eth32(Port32)  routed    down       up              N/A         N/A

Configuring the interface breakout mode (without Dynamic Port Breakout)

Example model & SONiC version (without Dynamic Port breakout support):

• Aurora 610
• Netberg SONiC: SONiC.202111-nba610-support

Intel Tofino does not support Dynamic Port Breakout and AutoNegotiation functions.

You’ll need to edit the /usr/share/sonic/device/x86_64-model_name-r0/model_profile/port_config.ini file to reconfigure the interface.

In this example, we split port 49 of Netberg Aurora 610 into 4x10G configuration and FireCode FEC.

admin@sonic:~$ sudo nano /usr/share/sonic/device/x86_64-netberg_aurora_610-r0/aurora-610/port_config.ini
Ethernet48      47            Ethernet48   47      25000   off      rs
Ethernet49      48            Ethernet49   48      10000   off      fc
Ethernet50      49            Ethernet50   48      10000   off      fc
Ethernet51      50            Ethernet51   48      10000   off      fc
Ethernet52      51            Ethernet52   48      10000   off      fc
Ethernet53      52,53,54,55   Ethernet53   49      100000  off      rs

After finishing the edit, the system config has to be re-generated:

admin@sonic:~$ sudo sonic-cfggen -H -k aurora-610 --preset t1 -p /usr/share/sonic/device/x86_64-netberg_aurora_610-r0/aurora-610/port_config.ini > /etc/sonic/config_db.json

Reboot the system.

This action will restore the system default config and erase all user changes.

Check the status:

admin@sonic:~$ show interface status | grep 'Ethernet49|Ethernet50|Ethernet51|Ethernet52'
Ethernet49           48      10G   9100     fc  Ethernet49  routed      up       up     N/A         N/A
Ethernet50           49      10G   9100     fc  Ethernet50  routed      up       up     N/A         N/A
Ethernet51           50      10G   9100     fc  Ethernet51  routed      up       up     N/A         N/A
Ethernet52           51      10G   9100     fc  Ethernet52  routed      up       up     N/A         N/A

Now the port management runs as described in this article – https://netbergtw.com/top-support/netberg-sonic/physical-interface-management/