After a factory reset, the login will be admin and password left blank.
What sort of problems are you having with adding the DLink? What is the existing modem/router device on your network?
A typical setup would be to connect the routers from LAN port to LAN port, and turn off DHCP on the DLink.
have a dlink 615 router and just want to add it to my existing network - solely for the purposes of extending my signal to the basement by having this one on the main floor - I thought I could do this. Additional prob is I reset it and don't have the password and can't connect it to the 192.168.0.1 site
help!

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