Ok, so i should use extra direct port between Summit3 and Summit4 for isc-2. Can i put all vlans on that extra port ? Now for isc-1, between summit1 and summit2, i'm using the same port for all vlans inculded isc and all works correct. If i put all vlans on this extra port I'm afraid about loop..
Below new version of graph:
![760935b2b31e4ef79fe2aac0ad54cf66_RackMultipart20150812-10576-jh6bgj-two-tier_mlag_but_isc1_isc2_on_one_port-v2_inline.png 760935b2b31e4ef79fe2aac0ad54cf66_RackMultipart20150812-10576-jh6bgj-two-tier_mlag_but_isc1_isc2_on_one_port-v2_inline.png](/t5/image/serverpage/image-id/1274i26D2AD1B12B840AB/image-size/large?v=v2&px=999)