M3400 Connectivity, One side 1000Mb and the other 100Mb

[gerardwest]

Here's the setup:

M3400 has a 1000Mb fiber connection to a MUX. The MUX, via SONET transport, has 100Mb connection to remote switch, a 6509.

Remote switch can see the ME3400 via cdp. ME3400 can't see remote switch via cdp. Remote switch see's the ME3400's arp entries, although no ping replies are received. The ME3400 doesn't have arp entires for the remote switch.

Communication seems to be only one way. The transport facility tests good. Any thoughts?

[umedryk]

The issue is due to proxy arp. The issue may be due the Layer 3 to Layer 2 resolution is not processed over the link. Check the "debug ip packet"output if it showing encapsulation failed message in the output. If it is so configure layer 3 to Layer 2 resolution.