Fastsnmp certs cloning my own sub modem sb5101

[Domkratos]

Ok, so from a lot more reading and coming across some stuff drewmerc posted, i've tried using putty to telnet into my unmoded modem, but all it does is return the issue "could not open connection to the host on port 23". Now like i said i did try this on my stock FW 5101, so maybe its not possible to do that. I also tried using fastsnmp, and snmp_admin to "capture the certs" i guess... Both of which just finished scanning, and it came back with nothing.
I'm guessing i scanned on the wrong ip range, or something... but any help with just capturing the certs from my subbed oem fw modem would be appreciated guys. even links of more shit to read, that can help.

thanks all