I bought an 1811 on ebay recently. The router came configured. The seller did not know the password, as it was programmed by a tech who no longer worked for him.
Basically, I want to reset it to factory default,and load SDM, and use that to configure it. Is this going to get me there? http://www.cisco.com/en/US/products/sw/iosswrel/ps5187/products_tech_note09186a00802017a1.shtml
Or will this blank everything out, and I'll have to reconfigure it before I can get SDM to load?