Doug - Usually CPE (customer premise equipment) devices are designed not to allow management (SNMP) access on the customer side of the device.
For practice, I would recommend getting a used "managed" switch or router off of Ebay or Craigslist, or enabling SNMP on one of your workstations.
Thanks for the info. I do have some old Cisco switches and routers. I will try it out on them. Just hoping I could see what is happening on my DSL modem.