Peter has just been hired as a network engineer and has recently been examining the company's core router configuration. He notices that the current configuration would allow an incoming packet from the Internet to have a source IP address within the $10\mathrm{.}0\mathrm{.}0\mathrm{.}0/8,172\mathrm{.}16\mathrm{.}0\mathrm{.}0/12,$ or $192\mathrm{.}168\mathrm{.}0\mathrm{.}0/16$ address space. Which of the following should Peter do$?$