Conf t  vlan 110 vlan 120 default int range gi1/0/19 - 20 int range gi1/0/19 - 20  switchport mode trunk

What Rick said. The configs aren't the same.  Anyway, see if the trunks are up and trunking the vlans you want. show int trunk

I manage a C3560 and have set the sdm-prefer like you said. Enter the command at the # prompt. Do not go to config t. My switch runs at layer 2 but has an IPv6 management address. Not sue if you must do this.

That's bizarre.  Are you sure your IP isn't in that range?  What's you subnet mask?If you're correct, this looks like a massive fail by your ISP.  I don't even know how they would be sending you those packets.  It would be interesting to do a wiresha...