Hi, I have a problem with a cat 3560, I have connected an old device and no MAC address is learned. I try to ping the device but no mac address are learned and I have not connectivity with it. I have seen with the command "sh controllers ethernet-controller Fax/y" how the counter "Invalid frames, too small" grow up. If I put a home switch (without management, vlans or STP) between the device and the 3560, then the problem is solve
I think that this conventional switch reformats the frames adding some zeros.
I have attempted to do a lot of probes, putting the port as a trunk (dot1q and ISL), using native vlan, voice vlan, access ports, force the mode and speed of port, disable QoS but without success.
In a 2950 it works fine. From what I read, the 2950 if receives a small frame forwards that frame without modify it, but the 3560 is more strict and discard the frame, furthermore if QoS is enabled the 3560 platform by default overrides de header QoS.
Can someone help me or knows something about this behavior?
