only they can fix there silly modem and system ! if dead.
"my old"
what does that mean>?
that is only a CABLE ONLY model. from Comcast (theirs)
that means
NO ROUTER. < never run lacking one. buy one.
SURFboard SB5101 DOCSIS 2.0 Cable Modem
no wifi at all,there just one Ethernet port (sublan)
best is add router (say netgear) to this this old modem
and then let the router do its job and all IOT, all work.
IOT is internet of THINGS. (all)
test wired first then play with wifi, last, set it up. per the routers manual
or ask
buy a router first , own one, not old , new , new are safe.
routers only not cable/router combo's
like Netgear AC750 on up.
R6020
like these (not docsis)
the costs are based on speed.
https://www.walmart.com/search?q=netgear&sort=price_low
you must RTM , to set up any router. Read the manual.
set SSID
use WPA1/2 mode
set in a wifi password, ( a good one, that is safe.)
check out the new Netgear that have preset SSID.
https://www.downloads.netgear.com/files/GDC/R6020/R6020_UM_EN.pdf
I like where Netgear is going with that. pre assigned at the factory,
and ready to run, no setup.. for noobs a big deal that.
but your are not locked out of settings at all, PAGE 57