I am not having any luck getting link between the Gig over copper ports on a CSS11503 and the fast ethernet ports on a 4006 Cat. I have been searching for a definitive answer on this in Cisco documentation but have ended up with just hints. I've tried cross-over and straight through cables. If I connect the gig port 1/1 on CSS A to gig port 1/1 on CSS B I do get link light. But if I connect gig port 1/1 on CSS A to any enabled fast ethernet port on a catalyst 4006 I get absolutely nothing.
This web site..offers a hint that Gig will not be able to figure out negotiation. Not the "Fast Ethernet Only":
"enables the CSS ports to automatically detect the network line speed (Fast Ethernet only) "
And when I try to hard code the gig interfaces to 100Mbps the CSS does not permit me to do so. Can anyone point me to something more definitive information about connecting CSS gig over copper interfaces to a fast ethernet switch? Thanks.