I have a modem with 2 ethernet ports. 1 goes to my router and the other directly to my pc. My printer is connected to my router wirelessly. I used to be able to print from my pc until recently. I could only get it to work if I plugged my pc into one of the ports on the router. Is there a work around for this? Router is Linksys WRT-1900 AC
The line from your modem to your router ... does it plug into the yellow ("internet") port on the router? If so, you have probably created 2 different networks that can't talk to each other. If this is the case, try putting your router in "bridge mode" (pg 33 of manual http://downloads.linksys.com/downloads/userguide/1224701614608/MAN_WRT1900AC_8820-01897_RevA00_EN_FR-CA_Comprehensive.pdf).
Alternatively, you can move the plug from the modem from the yellow port and into a blue port instead of the yellow. Make sure you turn off DHCP (pg 27).
After doing either of these, devices connected to the router will need to get new IP addresses. Restarting them is the easiest way to renew the IP address.