Routing from 2821 to RV042

[Rick Scheer]

I have a 2821 with 2 GE ports integrated.  I have one port G0/0, connected to my existing network, the is running on a CISCO RV042, small business router, which is acting as my firewall and connecting to the internet through a cable modem.  G0/1 is connected to a new network.  I am routing just fine between my existing network, through the 2821 to my new work.  I am natting from G0/1 to G0/0.  I can ping PCs on my new network, from PCs on my existing network, and vice versa.  What does not work, is connectivity to the internet from my 2821, or any pc on my new network.  I have a gateway of last resort, sending all packets not directed out G0/0, which connects to my SOHO router.

[danjone3]

There's not enough information to provide a definitive answer but the two most likely culprits are incorrect NATing or incorrect firewall configuration blocking the outgoing traffic.

Are you running NAT on the old network?  Does the new network NAT to the same outgoing (public) subnet?  Has the firewall been configured to allow traffic from the new network out to the Internet?  If you traceroute from the new network to a site on the Internet, where does the traffic stop?