Right now 168.com only displays the last part of the IP address. So if two repliers both have *.*.*.119 in the last part, it does not necessarily mean those two are the same person.
BTW, Comcast or AT&T generally does NOT bind your home network gateway to a static IP address. If you turn off your cable or DSL modem for 3 or 4 hours or longer, you should be assigned to a different IP address. So the last part of your IP address might change from 119 to 250 二百五