I have a brand new 3560, that I have configured to replace an existing 2651 router. I am using ports 23 and 24 to do this. Port 23 is setup to connect to my firewall, which is a server box, with Checkpoint installed. Port 24 is setup to connect to a port on an HP 4108gl chassis. When I plug the cables in for the new switch, there is no communication. I cannot ping the 3560 from the firewall, and the HP never picks up the MAC address of the 3560, and no ping from either side of the connection. I have the configs of the original 2651, and the 3560, if anyone wants to look at them. I am really banging my head on this, so any help would be greatly appreciated.
My e-mail is jheaton AT etp.ca.gov if anyone would like to see the config files.
Apologies, missed your reply. Have you checked the speed/duplex. If in doubt hardcode both ends and see if that helps.
Also can you post routing table from your router and the 3560 (if you can get them from both devices)