I have a Mac that connects wirelessly to a router downstairs. I have a 2nd router upstairs that I want to use with the mac, in which the mac provides an internet connection to that router. Can anyone help me with doing this? Thanks.
1. Make sure the 2nd router is off for now
2. Go to Dock/Finder-->Preferences-->Sharing
3. (Assuming OSX 10.7) Highlight the 2nd-to-last option (Internet Sharing)-->Select 'Wi-Fi' from the 'Share your connection from' drop-box
4. Click the check-box next to 'Ethernet' in the 'To computers using:' section and click the check-box next to 'Internet Sharing' to finally enable it.
5. Connect the ethernet cable from your Mac to your router's WAN/Internet port and turn your 2nd router on.
Assuming that 2nd router is set up for DHCP it should now see your ethernet-connected Mac as its gateway and use it as its internet source.