i've managed to set this up, with 4 switches
i used 2 ports on each switch for interconnect trunk (that makes 2 pairs of interconnected switches)
i used 2 ports on each switch and put them in dt-lacp (i have put dt-lacp on the source and destination)
then i connecteded thos dt-lacp ports to each other (connected the 4 switches all together)
i have noticed that any, non dt-lacp connection between switch would cause a huge broadcast storm, it is better to just unplug or disable all the other ports
config is like this on all 4 switches
trk1, port 23 and 24 for lacp interconnect (2 cables between a pair of switches for the switch interconnect)
trk2 dt-lacp port 21 and 23, i configured dt-lacp on all 4 switches
heartbeat port 20
is this correct?
result of sh lacp distributed on all 4 switches is
Local Port Status:
LACP Trunk Port LACP Admin Oper
Port Enabled Group Status Partner Status Key Key
---- ------- ------- ------- ------- ------- ------ ------
23 Active Trk2 Up Yes Success 0 291
24 Active Trk2 Up Yes Success 0 291
Remote Port Status:
LACP Trunk Port LACP Oper
Port Enabled Group Status Partner Status Key
---- ------- ------- ------- ------- ------- ------
23 Active Trk2 Up Yes Success 0
24 Active Trk2 Up Yes Success 0
so by configuring the dt-lacp on all the ports that connect to switches it makes 1 big Trk2
i was confused by the fact that you would set up dt-lacp on interconnected switch, and normal lacp on the destination, but the destination is also an interconnected switch, so i used dt-lacp on source ports and destination ports
is this the correct way?
by the way, i use this to make 4 6600 switches as 1 'stack', but is this the right way to do for a backbone to connect the storage to the servers?
top two switches are connected to storage, bottom two switches are connected to flex-10, and dl 580
next thing to do is use the dt-lacp to make trunks to the storage servers on the top switches, and also use dt-lacp to enable active/active shared uplink sets.
the dl580 have separate physical ports, i will not put them in trunk, but rely on the mpio only