Telstra Smart Modem Does Not Allow Port Forwarding

An internet service using a Telstra Business Smart Modem (Netgear V7610) may not accept connections through forwarded ports.

Additionally, a tracert command may time out before reaching the service's public IP address.

This may occur if Respond to Ping on Internet Port is unticked under Advanced → Setup → WAN Setup.

(This setting may have been turned off after a firmware update.)