Run these commands on each switch to bring up the interfaces.
cumulus@cumulus:mgmt:~$ net add interface swp1,swp2,swp3 cumulus@cumulus:mgmt:~$ net commit cumulus@cumulus:mgmt:~$ exit
cumulus@cumulus:mgmt:~$ net add interface swp1,swp2,swp3 cumulus@cumulus:mgmt:~$ net commit cumulus@cumulus:mgmt:~$ exit
cumulus@cumulus:mgmt:~$ net add interface swp1,swp2 cumulus@cumulus:mgmt:~$ net commit cumulus@cumulus:mgmt:~$ exit