I installed a WS-X6748-SFP in my 6509 with two sup 720 base and it changed the switchmode from flow-through to truncated which I believe is due to the fact that i had one non fabrice enabled blade WS-X6348-RJ-45 in it.
%SYS-3-FAB_CHNGMODE:System switching mode is being changed to truncated mode
in truncated switching mode my network performace severely degraded and we eventually had to remove these cards to restore services.
I want to know why it would degrade the performance, is it becasue it writes the first 64 bytes of frame over switch fabric and rest over the blade or something else?
What if I force to use bus mode? any caveates on that?
what is the best switching mode when i have fabric enable module but possibility that i can have one or two non fabric module as well.