[horseman]

Originally Posted by craigj2k12

you can run it to anything that replies to a ping

…..assuming the IP to which you configured the monitor to doesn't change as in the scenario under discussion.

As soon as the OP placed the SHub in modem/bridge mode and rebooted then the cmts essentially detected the cpe mac address had changed and dhcp'd a new ip.
He'd essentially have to configure a new TBB monitor as well as ensuring his (new) end device had it's WAN icmp echo enabled.
Alternatively he'd have to "sniff" the SH imbedded router mac and clone that into his new end device to avoid the ip changing and continue to use his existing TBB graph.