networking strangeness - Cisco + Macs - FIXED

[pete]

I have a new mac media lab. If I plug a windows or linux box into a network point, it gets an IP address assigned by dhcp no problems and can access everything on the network and beyond.

 

If I plug an imac or macbook in, it fails to get an IP address. If I set a static IP on a mac it can browse up to a certain switch, but can't ping any further. The switch is a Cisco C2950T, set up exactly as all the others with all ports in a single VLAN.

 

At least 3 of these machines (2x imac and 1x macbook) are "known good" - they've worked fine on another part of the school network.

 

Does anyone here have a clue as to why these macs don't work (despite working with these settings on other parts of the network), but a windows and linux box will? The switch doesn't give any clue as to why this might be and seems quite happy from looking at the logs.

[pete]

Ok found out what it is.

 

Smartports was set up on the switch. If you select "desktop" as the port settings on the switch, it seems to prevent the mac from getting out from the switch - note sure why. Clearing the smartports setting (set to "None" makes it work fine.

 

Annoying, but at least I know now.