set protocols bfd peer 45.86.XXX.XXX profile 'internal'
set protocols bfd peer 45.86.XXX.XXX source interface 'tun1'
set protocols bfd profile internal echo-mode
set protocols bfd profile internal interval echo-interval '300'

alyx@vyos# del protocols bfd profile internal interval 
[edit]
alyx@vyost# commit

Failed to execute bfd  profile internal   no echo transmit-interval 300
exit exit "bfd --  profile internal --   no echo transmit-interval 300
--  exit -- exit" we failed to remove this command % Unknown command: no
echo transmit-interval 300  Failed to execute bfd  profile internal no
echo receive-interval 300  exit exit "bfd --  profile internal -- no
echo receive-interval 300 --  exit -- exit" we failed to remove this
command % Unknown command:   no echo receive-interval 300
[3551821|mgmtd] sending configuration [3551822|zebra] sending
configuration [3551823|ripd] sending configuration [3551824|ripngd]
sending configuration [3551825|ospfd] sending configuration
[3551826|ospf6d] sending configuration [3551827|ldpd] sending
configuration [3551828|bgpd] sending configuration [3551829|isisd]
sending configuration [3551833|babeld] sending configuration
[3551821|mgmtd] done [3551836|watchfrr] sending configuration
[3551822|zebra] done [3551823|ripd] done [3551838|staticd] sending
configuration [3551839|bfdd] sending configuration [3551824|ripngd] done
[3551826|ospf6d] done [3551827|ldpd] done [3551825|ospfd] done
[3551829|isisd] done Waiting for children to finish applying config...
[3551842|pim6d] sending configuration [3551828|bgpd] done
[3551833|babeld] done [3551836|watchfrr] done [3551838|staticd] done
[3551842|pim6d] done [3551839|bfdd] done [3551846|mgmtd] sending
configuration [3551847|zebra] sending configuration [3551848|ripd]
sending configuration [3551849|ripngd] sending configuration
[3551850|ospfd] sending configuration [3551851|ospf6d] sending
configuration [3551852|ldpd] sending configuration [3551853|bgpd]
sending configuration [3551854|isisd] sending configuration
[3551858|babeld] sending configuration [3551861|watchfrr] sending
configuration [3551863|staticd] sending configuration [3551864|bfdd]
sending configuration [3551847|zebra] done [3551849|ripngd] done
[3551846|mgmtd] done Waiting for children to finish applying config...
[3551848|ripd] done [3551867|pim6d] sending configuration
[3551851|ospf6d] done [3551854|isisd] done [3551850|ospfd] done
[3551852|ldpd] done [3551853|bgpd] done [3551858|babeld] done
[3551861|watchfrr] done [3551863|staticd] done [3551867|pim6d] done
[3551864|bfdd] done

[[protocols bfd]] failed
Commit failed